Assertion Failed

rECOMBINAToR
Tue, 30 Dec 2025 21:07:55 +0000
Blueprint

Hi Guys,

I got this error continuously, ‘kinda’ randomly:

[2025.12.30-19.09.36:566][162]LogWindows: Error: appError called: Assertion failed: SyncPosition.NextMarkerName != NAME_None [File:D:\build++UE5\Sync\Engine\Source\Runtime\Engine\Private\Animation\AnimSequence.cpp] [Line: 4307]

I cannot find any clue what to check. I got this error mostly in editor, but my friend managed to recreate in a packaged project. It mostly occurs when I’m rolling after landing, but not every time. My friend did not roll at all and managed to recreate.

I know that complete solution cannot be given without the whole project, but I need only a direction where to start.

How can I find this AnimSequence.cpp file to check the line that the log mentions? Should I check the Animation Blueprint, the animation sequences or what? How should I get a more precise error message?

Thank you in advance.

3 posts - 2 participants