Help me i'm new on MCreator

Hi, I started modding about one week ago. I’m starting with a good first impression since MCreator seems easy to use and I already have some skills in programming.

However, I’m having trouble understanding some features — or rather how they actually work. I started creating an incubator for my pet eggs for my mod, and despite writing a rather laborious piece of code for the incubator’s functionality, I always get the same error when I launch the game :
 

> Task :compileJava FAILED 
Note: SpongePowered MIXIN Annotation Processor Version=0.8.5 
Note: Supported obfuscation types: ObfuscationServiceMCP supports [searge,notch] 
C:\Users\nxbelixm\MCreatorWorkspaces\eggpet\src\main\java\net\mcreator\eggpet\init\EggpetModBlockEntities.java:18: error: cannot find symbol 
    public static final RegistryObject<BlockEntityType<PrimitiveIncubatorBlockEntity>> PRIMITIVE_INCUBATOR = register("primitive_incubator", EggpetModBlocks.PRIMITIVE_INCUBATOR, PrimitiveIncubatorBlockEntity::new); 
                                                       ^ 
  symbol:   class PrimitiveIncubatorBlockEntity 
  location: class EggpetModBlockEntities 
1 error 
FAILURE: Build failed with an exception. 
* What went wrong: 
Execution failed for task ':compileJava'. 
> Compilation failed; see the compiler output below. 
  Note: SpongePowered MIXIN Annotation Processor Version=0.8.5 
  1 error 
* Try: 
> Run with --scan to generate a Build Scan (powered by Develocity). 
BUILD FAILED in 2s

I don’t understand why. I did everything properly: I placed the procedure where it’s supposed to run and set up the GUI as well, but the game just never wants to launch…

Please help me, I’m begging you, thx.