error build mob with imported model

Hello sorry i create a new topic becose i can't find a solution in another.

i have problem with all the 3D model that I tried to import from blockbench. when I try to launch "the demo" a message is displayed:

ps: sorry im french so my english is not verry good 

the error message:

Executing 
    Gradle task: runClient

Build 
    info: MCreator 2020.4.32115, forge-1.15.2, 64-bit, 4038 MB, Windows 10, 
    JVM 1.8.0_252, JAVA_HOME: C:\Program Files\Pylo\MCreator\jdk

> 
    Configure project :

New 
    Dep: net.minecraftforge:forge:1.15.2-31.2.0_mapped_snapshot_20200514-1.15.1

> 
    Task :compileJava FAILED

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:178: 
    error: cannot find symbol 
 
         private final ModelPart head;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:179: 
    error: cannot find symbol 
 
         private final ModelPart head2;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:180: 
    error: cannot find symbol 
 
         private final ModelPart beak1;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:181: 
    error: cannot find symbol 
 
         private final ModelPart beak2;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:182: 
    error: cannot find symbol 
 
         private final ModelPart body;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:183: 
    error: cannot find symbol 
 
         private final ModelPart tail;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:184: 
    error: cannot find symbol 
 
         private final ModelPart wing0;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:185: 
    error: cannot find symbol 
 
         private final ModelPart wing1;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:186: 
    error: cannot find symbol 
 
         private final ModelPart feather;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:187: 
    error: cannot find symbol 
 
         private final ModelPart leg0;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:188: 
    error: cannot find symbol 
 
         private final ModelPart leg1;

 
                       ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:233: 
    error: cannot find symbol 
 
         public void render(MatrixStack matrixStack, VertexConsumer buffer, 
    int packedLight, int packedOverlay, float red, float green, float blue,

 
                                                     ^

 
     symbol:   class VertexConsumer

 
     location: class Modelblackbird

C:\Users\Tristan\MCreatorWorkspaces\molten_obsidian\src\main\java\net\mcreator\moltenobsidian\entity\BlackbirdEntity.java:248: 
    error: cannot find symbol 
 
         public void setRotationAngle(ModelPart bone, float x, float y, float 
    z) {

 
                                      ^

 
     symbol:   class ModelPart

 
     location: class Modelblackbird

13 
    errors

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#se…

BUILD 
    FAILED in 4s

1 
    actionable task: 1 executed

BUILD 
    FAILED

Task 
    completed in 6713 milliseconds

help me please i tried with many moded entity and it's dont work T^T