Metahuman constant crashing in sequencer under AssertionFailed Sparse Array

Hey guys, anyone else get constant crashing when using metahumans in their sequencer? I have to delete all my metahumans before loading the sequencer, then undo the delete just to stop it from crashing upon loading, but it still crashes eventually.
Here’s the key error:
Assertion failed: !AllocationFlags[Index] [File:D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\SparseArray.h] [Line: 94]

Any ideas?

Hi, exact same issue here. Have not been able to find a solution yet.

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I haven’t found any complete 100% fixes, but here are some things I’ve been doing that seem to help reduce the number of these crashes a lot:

  1. Turn off thumbnails in sequencer- Basically every time you load the sequencer it looks inside every sequence and takes a picture, so if there’s anything crashy in that sequence it crashes it
  2. Delete metahumans, Load Sequence, undo delete- So if your sequence keeps crashing when you open it, I found that it’s because there’s something in the metahumans being referenced in the timelime before it’s all loaded, so if you delete metahumans, then load the sequence, then hit undo to bring the metahumans back it seems to help reduce crashing
  3. Don’t key “Animation Mode” “Anim Class” or “Disable Post process blueprint” on the metahuman face, a lot of tutorials say to key these but there’s no reason and it makes it more crashy
  4. Bake control rigs into animations, delete the control rigs, then apply it as an animation, especially if you were using any constraints
  5. Delete the empty control rigs if they aren’t being used, never leave empty control rig channels

Following these steps has helped me a lot, but, I still can count on crashes fairly frequently, but now it’s ever 30 min instead of every 2-5 min

I just did something that is helping a lot- always bake all control rigs down to animation sequences, that seems to significantly reduce crashing