If the source mesh nodes used to create blendshape targets aren’t deleted before exporting the skeletal mesh to FBX, and this FBX is imported, unreal hangs perpetually while trying to import the morph targets. Deleting the nodes and exporting again resolved the issue and prevents the crash, but I’d like some catch for this that doesn’t require force quitting the editor.
Exporting the skeleton and meshes only doesn’t fix the issue.
From what you have described you create a skeletal mesh and morph target inside of Maya. Then you exported this as an .fbx to UE4. After doing this UE4 continues to load but never does. When deleting nodes and exporting them again this solves your issue.
If you would please link me your DxDiag and your Maya File so I can attempt to reproduce this issue on my end. This way I can, without guesswork and narrowing down any factors that could cause this between my machine and yours, attempt to recreate the freeze that you are experiencing.
Due to inactivity and tracking purposes I will be marking this thread as closed. If you are still having a problem then please post again. I will then continue to investigate this issue at that time.