capital letters in mod display name causes build errors

Status
Fixed
Issue description
i was updating my mod and just capitalising item and block names then i changed the mod display name from "skyblock items" to "Skyblock Items" and about 10 of my mod elements had errors
log (i dont know is this is correct):
Executing Gradle task: build 
Build info: MCreator 2020.3.18613 EAP (18613), forge-1.15.2, 64-bit, 3973 MB, Windows 10, JVM 1.8.0_252, JAVA_HOME: C:\Users\lloyd\Desktop\MCreatorEAP20203b18613\jdk 
> Configure project : 
New Dep: net.minecraftforge:forge:1.15.2-31.1.63_mapped_snapshot_20200225-1.15.1 
> Task :compileJava 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\Skyblockitems.java:42: error: class SkyblockItems is public, should be declared in a file named SkyblockItems.java 
public class SkyblockItems { 
       ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\SkyblockitemsElements.java:46: error: class SkyblockItemsElements is public, should be declared in a file named SkyblockItemsElements.java 
public class SkyblockItemsElements { 
       ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\SkyblockitemsVariables.java:17: error: class SkyblockItemsVariables is public, should be declared in a file named SkyblockItemsVariables.java 
public class SkyblockItemsVariables { 
       ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\BigcraftingtableBlock.java:44: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\BigcraftingtableBlock.java:52: error: package SkyblockitemsElements does not exist 
public class BigcraftingtableBlock extends SkyblockitemsElements.ModElement { 
                                                                ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\BigcraftingtableBlock.java:51: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\BigcraftingtableBlock.java:57: error: cannot find symbol 
   public BigcraftingtableBlock(SkyblockitemsElements instance) { 
                                ^ 
  symbol:   class SkyblockitemsElements 
  location: class BigcraftingtableBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrateBlock.java:30: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrateBlock.java:36: error: package SkyblockitemsElements does not exist 
public class CrateBlock extends SkyblockitemsElements.ModElement { 
                                                     ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrateBlock.java:35: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrateBlock.java:39: error: cannot find symbol 
   public CrateBlock(SkyblockitemsElements instance) { 
                     ^ 
  symbol:   class SkyblockitemsElements 
  location: class CrateBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrusibleBlock.java:24: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrusibleBlock.java:30: error: package SkyblockitemsElements does not exist 
public class CrusibleBlock extends SkyblockitemsElements.ModElement { 
                                                        ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrusibleBlock.java:29: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\CrusibleBlock.java:33: error: cannot find symbol 
   public CrusibleBlock(SkyblockitemsElements instance) { 
                        ^ 
  symbol:   class SkyblockitemsElements 
  location: class CrusibleBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\DiamondcrateBlock.java:23: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\DiamondcrateBlock.java:29: error: package SkyblockitemsElements does not exist 
public class DiamondcrateBlock extends SkyblockitemsElements.ModElement { 
                                                            ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\DiamondcrateBlock.java:28: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\DiamondcrateBlock.java:32: error: cannot find symbol 
   public DiamondcrateBlock(SkyblockitemsElements instance) { 
                            ^ 
  symbol:   class SkyblockitemsElements 
  location: class DiamondcrateBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcrucibleBlock.java:54: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcrucibleBlock.java:63: error: package SkyblockitemsElements does not exist 
public class FiredcrucibleBlock extends SkyblockitemsElements.ModElement { 
                                                             ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcrucibleBlock.java:62: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcrucibleBlock.java:68: error: cannot find symbol 
   public FiredcrucibleBlock(SkyblockitemsElements instance) { 
                             ^ 
  symbol:   class SkyblockitemsElements 
  location: class FiredcrucibleBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcruciblelavaBlock.java:23: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcruciblelavaBlock.java:29: error: package SkyblockitemsElements does not exist 
public class FiredcruciblelavaBlock extends SkyblockitemsElements.ModElement { 
                                                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcruciblelavaBlock.java:28: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\FiredcruciblelavaBlock.java:32: error: cannot find symbol 
   public FiredcruciblelavaBlock(SkyblockitemsElements instance) { 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: class FiredcruciblelavaBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\IroncrateBlock.java:23: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\IroncrateBlock.java:29: error: package SkyblockitemsElements does not exist 
public class IroncrateBlock extends SkyblockitemsElements.ModElement { 
                                                         ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\IroncrateBlock.java:28: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\IroncrateBlock.java:32: error: cannot find symbol 
   public IroncrateBlock(SkyblockitemsElements instance) { 
                         ^ 
  symbol:   class SkyblockitemsElements 
  location: class IroncrateBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\NetherstarblockBlock.java:29: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\NetherstarblockBlock.java:36: error: package SkyblockitemsElements does not exist 
public class NetherstarblockBlock extends SkyblockitemsElements.ModElement { 
                                                               ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\NetherstarblockBlock.java:35: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\NetherstarblockBlock.java:39: error: cannot find symbol 
   public NetherstarblockBlock(SkyblockitemsElements instance) { 
                               ^ 
  symbol:   class SkyblockitemsElements 
  location: class NetherstarblockBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\ObsidiancrateBlock.java:23: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\ObsidiancrateBlock.java:29: error: package SkyblockitemsElements does not exist 
public class ObsidiancrateBlock extends SkyblockitemsElements.ModElement { 
                                                             ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\ObsidiancrateBlock.java:28: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\ObsidiancrateBlock.java:32: error: cannot find symbol 
   public ObsidiancrateBlock(SkyblockitemsElements instance) { 
                             ^ 
  symbol:   class SkyblockitemsElements 
  location: class ObsidiancrateBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\SeiveBlock.java:30: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\SeiveBlock.java:36: error: package SkyblockitemsElements does not exist 
public class SeiveBlock extends SkyblockitemsElements.ModElement { 
                                                     ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\SeiveBlock.java:35: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\SeiveBlock.java:39: error: cannot find symbol 
   public SeiveBlock(SkyblockitemsElements instance) { 
                     ^ 
  symbol:   class SkyblockitemsElements 
  location: class SeiveBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinymagmablockBlock.java:29: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinymagmablockBlock.java:35: error: package SkyblockitemsElements does not exist 
public class TinymagmablockBlock extends SkyblockitemsElements.ModElement { 
                                                              ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinymagmablockBlock.java:34: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinymagmablockBlock.java:38: error: cannot find symbol 
   public TinymagmablockBlock(SkyblockitemsElements instance) { 
                              ^ 
  symbol:   class SkyblockitemsElements 
  location: class TinymagmablockBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinyslimeblockBlock.java:29: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinyslimeblockBlock.java:35: error: package SkyblockitemsElements does not exist 
public class TinyslimeblockBlock extends SkyblockitemsElements.ModElement { 
                                                              ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinyslimeblockBlock.java:34: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\block\TinyslimeblockBlock.java:38: error: cannot find symbol 
   public TinyslimeblockBlock(SkyblockitemsElements instance) { 
                              ^ 
  symbol:   class SkyblockitemsElements 
  location: class TinyslimeblockBlock 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\CaveCommand.java:12: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\CaveCommand.java:22: error: package SkyblockitemsElements does not exist 
public class CaveCommand extends SkyblockitemsElements.ModElement { 
                                                      ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\CaveCommand.java:21: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\CaveCommand.java:23: error: cannot find symbol 
   public CaveCommand(SkyblockitemsElements instance) { 
                      ^ 
  symbol:   class SkyblockitemsElements 
  location: class CaveCommand 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\DebugCommand.java:11: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\DebugCommand.java:21: error: package SkyblockitemsElements does not exist 
public class DebugCommand extends SkyblockitemsElements.ModElement { 
                                                       ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\DebugCommand.java:20: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\DebugCommand.java:22: error: cannot find symbol 
   public DebugCommand(SkyblockitemsElements instance) { 
                       ^ 
  symbol:   class SkyblockitemsElements 
  location: class DebugCommand 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IsCommand.java:12: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IsCommand.java:22: error: package SkyblockitemsElements does not exist 
public class IsCommand extends SkyblockitemsElements.ModElement { 
                                                    ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IsCommand.java:21: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IsCommand.java:23: error: cannot find symbol 
   public IsCommand(SkyblockitemsElements instance) { 
                    ^ 
  symbol:   class SkyblockitemsElements 
  location: class IsCommand 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IslandCommand.java:12: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IslandCommand.java:22: error: package SkyblockitemsElements does not exist 
public class IslandCommand extends SkyblockitemsElements.ModElement { 
                                                        ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IslandCommand.java:21: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\IslandCommand.java:23: error: cannot find symbol 
   public IslandCommand(SkyblockitemsElements instance) { 
                        ^ 
  symbol:   class SkyblockitemsElements 
  location: class IslandCommand 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartCommand.java:12: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartCommand.java:22: error: package SkyblockitemsElements does not exist 
public class StartCommand extends SkyblockitemsElements.ModElement { 
                                                       ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartCommand.java:21: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartCommand.java:23: error: cannot find symbol 
   public StartCommand(SkyblockitemsElements instance) { 
                       ^ 
  symbol:   class SkyblockitemsElements 
  location: class StartCommand 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartinginventoryCommand.java:12: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartinginventoryCommand.java:22: error: package SkyblockitemsElements does not exist 
public class StartinginventoryCommand extends SkyblockitemsElements.ModElement { 
                                                                   ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartinginventoryCommand.java:21: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StartinginventoryCommand.java:23: error: cannot find symbol 
   public StartinginventoryCommand(SkyblockitemsElements instance) { 
                                   ^ 
  symbol:   class SkyblockitemsElements 
  location: class StartinginventoryCommand 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StopCommand.java:12: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StopCommand.java:22: error: package SkyblockitemsElements does not exist 
public class StopCommand extends SkyblockitemsElements.ModElement { 
                                                      ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StopCommand.java:21: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\command\StopCommand.java:23: error: cannot find symbol 
   public StopCommand(SkyblockitemsElements instance) { 
                      ^ 
  symbol:   class SkyblockitemsElements 
  location: class StopCommand 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\entity\PetrockEntity.java:32: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\entity\PetrockEntity.java:38: error: package SkyblockitemsElements does not exist 
public class PetrockEntity extends SkyblockitemsElements.ModElement { 
                                                        ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\entity\PetrockEntity.java:37: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\entity\PetrockEntity.java:40: error: cannot find symbol 
   public PetrockEntity(SkyblockitemsElements instance) { 
                        ^ 
  symbol:   class SkyblockitemsElements 
  location: class PetrockEntity 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\BigGui.java:39: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\BigGui.java:40: error: cannot find symbol 
import net.mcreator.skyblockitems.Skyblockitems; 
                                 ^ 
  symbol:   class Skyblockitems 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\BigGui.java:47: error: package SkyblockitemsElements does not exist 
public class BigGui extends SkyblockitemsElements.ModElement { 
                                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\BigGui.java:46: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\BigGui.java:50: error: cannot find symbol 
   public BigGui(SkyblockitemsElements instance) { 
                 ^ 
  symbol:   class SkyblockitemsElements 
  location: class BigGui 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\CrusibleGUIGui.java:44: error: package SkyblockItemsElements does not exist 
public class CrusibleGUIGui extends SkyblockItemsElements.ModElement { 
                                                         ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\CrusibleGUIGui.java:43: error: package SkyblockItemsElements.ModElement does not exist 
@SkyblockItemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\CrusibleGUIGui.java:47: error: cannot find symbol 
   public CrusibleGUIGui(SkyblockItemsElements instance) { 
                         ^ 
  symbol:   class SkyblockItemsElements 
  location: class CrusibleGUIGui 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\IslandsGui.java:37: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\IslandsGui.java:38: error: cannot find symbol 
import net.mcreator.skyblockitems.Skyblockitems; 
                                 ^ 
  symbol:   class Skyblockitems 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\IslandsGui.java:45: error: package SkyblockitemsElements does not exist 
public class IslandsGui extends SkyblockitemsElements.ModElement { 
                                                     ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\IslandsGui.java:44: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\gui\IslandsGui.java:48: error: cannot find symbol 
   public IslandsGui(SkyblockitemsElements instance) { 
                     ^ 
  symbol:   class SkyblockitemsElements 
  location: class IslandsGui 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\item\BadpaperItem.java:11: error: cannot find symbol 
import net.mcreator.skyblockitems.SkyblockitemsElements; 
                                 ^ 
  symbol:   class SkyblockitemsElements 
  location: package net.mcreator.skyblockitems 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\item\BadpaperItem.java:14: error: package SkyblockitemsElements does not exist 
public class BadpaperItem extends SkyblockitemsElements.ModElement { 
                                                       ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\item\BadpaperItem.java:13: error: package SkyblockitemsElements.ModElement does not exist 
@SkyblockitemsElements.ModElement.Tag 
                                 ^ 
C:\Users\lloyd\.mcreator\workspace\skyblockitems\src\main\java\net\mcreator\skyblockitems\item\BadpaperItem.java:17: error: cannot find symbol 
   public BadpaperItem(SkyblockitemsElements instance) { 
                       ^ 
  symbol:   class SkyblockitemsElements 
  location: class BadpaperItem 
100 errors 
> Task :compileJava FAILED 
FAILURE: Build failed with an exception. 
* What went wrong: 
Execution failed for task ':compileJava'. 
> Compilation failed; see the compiler error output for details. 
* Try: 
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights. 
* Get more help at https://help.gradle.org 
Deprecated Gradle features were used in this build, making it incompatible with Gradle 5.0. 
Use '--warning-mode all' to show the individual deprecation warnings. 
See https://docs.gradle.org/4.10.3/userguide/command_line_interface.html#sec:command_line_warnings 
BUILD FAILED in 18s 
1 actionable task: 1 executed 
BUILD FAILED
Issue comments

I can confirm this bug. I will fix it in 2020.3.
For now, you can work around this bug by Build & run -> Regenerate code and build after the name change.