The deadlock occurs when attempting to cancel compression during animation sequence destruction. The compression thread ends up deadlocking with the game thread, which is the one requesting the cancellation.
The issue occurs when attempting to overwrite an existing animation. Specifically, we load the package containing the animation, and shortly after it is loaded (while compression is still in progress), we attempt to overwrite it with a new one. As a result, the animation is destroyed, compression cancellation is requested, and the deadlock occurs.
Refer to attached image
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-364179 in the post.
| 1 |
| Component | UE - Anim - Runtime - Anim Blueprints |
|---|---|
| Affects Versions | 5.7 |
| Target Fix | 5.8 |
| Created | Feb 5, 2026 |
|---|---|
| Updated | Feb 6, 2026 |