Unreal Engine Issues
Unreal Engine Issues
AnimNotify serialization crash in editor
UE - Runtime - Animation - Mar 15, 2026The crash is caused by changing the variable type of an AnimNotify that is already referenced by a montage. This issue cannot be reproduced in 5.6. ...
Crash on iOS9 when using Apple's CFNetwork library
UE - Platform - Mobile - Dec 6, 2016Many clients have hit a crash due to an Apple library using operator delete on a memory block that was not allocated with operator new. This happens with the following callstack on iOS9 in UE4.13 o ...
MotionWarping does not recognize new MontageInstance with the same montage
UE - Characters - Animation - Jan 11, 2023When the same AnimMonotage is played again while moving with MotionWarping & RootMotion, UAnimNotifyState_MotionWarping does not recognize it. From licensee: The issue was that in URootMotionMod ...
[CrashReport] Access violation - FLandscapeEditDataInterface::SetAlphaData()
UE - LD & Modeling - Terrain - Landscape - Jul 19, 2017This is a common crash affecting users in 4.15 and 4.16. This callstack was previously linked to [Link Removed], but that had a specific repro case that was fixed in 4.14. Users are not providing ...
Changing a Media Player asset from Stream Mode: FromURL to From Memory crashes the editor
Tools - Dec 30, 2014Changing a Media Player asset from Stream Mode: FromURL to From Memory crashes the editor. In 4.8, the editor crashes immediately upon changing that value, with no crash report. In 4.6 and 4.7 Pre ...
Crash when quick binding a function in a class that extends LevelSequenceDirector
UE - Anim - Sequencer - Sep 16, 2020The purpose was to create a Level Sequence Director inheritance class so that the same event could be reused in multiple sequencers. Attempting to quick-bind this base Level Sequence Director event ...
Issue with importing alembic files: the skeletal mesh asset doesn't contain LOD description
UE - Editor - Open File Formats - Sep 15, 2026Helloo everyone!! 😄 We are experiencing an issue with importing skeletal meshes from alembic. For reference, this issue happens in vanilla engine 5.7.4, but it doesn't occur in versions 5.6.x. 1) ...
If using SetAlignmentInViewport in Construct, the value with it is ignored
UE - AI Workflows - UI Systems - UMG - Jan 27, 2023If SetAlignmentInViewport is called in the UMG Construct, it is ignored internally. This is due to a change that came in 5.1, so it worked fine in 5.0. First, when the Set Alignment in Viewport nod ...
Shipping build crash when unplugging then replugging Oculus HMD
UE - Platform - XR - Nov 9, 2016Game crashes in shipping build when un-pluging the Oculus HMD, then plugging it back in. Confirmed in 4.13.2 from the launcher, did not repro via same steps in 4.14 preview 3 ...
Open Formats: Interchange Import Runtime - Interchange ImportAssetAsync runtime GLB import — materials, textures, tangents, and shaders non-functional in packaged builds (6 issues, UE 5.7.4)
UE - Editor - Open File Formats - Apr 30, 2026Description* We are using Interchange's `UInterchangeManager::ImportAssetAsync()` to import GLB files at runtime in a packaged (Shipping) application. The orchestration layer (`ImportInternal` in `In ...