When SkeletalMeshComponent have not Skeletal Mesh ,the GPUSkinCache had Exception.the
check(DispatchData.PreviousPositionBuffer != DispatchData.PositionBuffer);
could not passed.
In my project , my character`s SkeletalMeshComponent had not set any mesh.because I made a Component to AsynLoad Mesh Asset and GetMesh()->SetSkeletalMesh() when Finished.
So It have Runtime Exception.until I set a proxy mesh(I made another capsule mesh and skinned it onto my skeleton) to it as default value.
I have not remember which function because I read source code and find many function had check(DispatchData.PreviousPositionBuffer != DispatchData.PositionBuffer);
so I think maybe flash GPU Skin Cache had not test the SkeletalMesh is valid or not?