how do I fix this
Assertion failed: !Primitive->SceneProxy [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Renderer/Private/RendererScene.cpp] [Line: 1221]
Primitive has already been added to the scene!
0x00007ffae01bcd29 KERNELBASE.dll!UnknownFunction []
Crash in runnable thread TaskGraphThreadHP 7