If you see the UE5 UHT error (Could not find definition for module 'MyModule'), it means the Unreal Header Tool can’t locate your module. This often happens when the module isn’t registered in Build.cs or there’s a typo in the module name. To fix this, ensure your module is properly defined in Build.cs:

public class MyModule : ModuleRules {  
  public MyModule(ReadOnlyTargetRules Target) : base(Target) { /* ... */ }  
}  

This resolves the Unreal Engine 5 module definition error.