MCreator crashes when a custom character model is used

You can't just change .md3 to .java. This is normal. You need to make proper .java model.

Techne for example even has the default biped model built in, but if you need steve model, you even have biped as default model option in MCreator.

how we can change .java in .md3 ? that don't pin up 

Sorry, I made a typo :D

You can't just change .md3 to .java. This is normal. You need to make proper .java model.

You can't

ho, yeah, 

but how we can do to prevent it from crashing because there are custom model entity ?

but how we can do to prevent it from crashing because there are custom model entity ?

Crashing -> Logs? Error messages?

that is the message : 

Executing Gradle task: runClient
Build info: MCreator 2020.2.14217, 1.14.4, 64-bit, 12184 MB, Windows 8, JVM 1.8.0_232, JAVA_HOME: C:\Program Files\Pylo\MCreator\jdk
> Configure project :
New Dep: net.minecraftforge:forge:1.14.4-28.2.3_mapped_snapshot_20190719-1.14.3
> Task :compileJava FAILED
C:\Users\Clotilde Rault\MCreatorWorkspaces\botanimaniac\src\main\java\net\mcreator\botanimaniac\entity\AmmoutEntity.java:233: error: cannot find symbol       public void render(MatrixStack matrixStack, IVertexBuilder buffer, int packedLight, int packedOverlay, float red, float green, float blue,
                         ^
  symbol:   class MatrixStack
  location: class Modelcustom_model
C:\Users\Clotilde Rault\MCreatorWorkspaces\botanimaniac\src\main\java\net\mcreator\botanimaniac\entity\AmmoutEntity.java:233: error: cannot find symbol       public void render(MatrixStack matrixStack, IVertexBuilder buffer, int packedLight, int packedOverlay, float red, float green, float blue,
                                                  ^
  symbol:   class IVertexBuilder
  location: class Modelcustom_model
2 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/4.9/userguide/command_line_interface.html#sec:c…
BUILD FAILED in 3s
1 actionable task: 1 executed
BUILD FAILED

You are using 1.15.2 custom model for 1.14.4 mod

and how I can get it to 1.14 ?

To set model version in Blockbench, go to File -> Project -> Export version.

You will need to recreate these I think