Unreal Engine Issues
Unreal Engine Issues
Niagara color picker user parameter preview no longer updates until confirmation
UE - Rendering - Architecture - Niagara - Apr 18, 2025Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...
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 ...
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 ...
Editor crash when compiling blueprint that contains an implemented interface after removing return node
UE - Gameplay - Blueprint - Apr 8, 2015If a return node is removed from an interface that has been implemented in a blueprint, compiling the blueprint will cause a crash. Crash Reporter: [Link Removed] Frequency: 2/2 ...
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 ...
SpringArmComponent with "Use Camera Lag Substepping" does not handle fluctuating frame rates correctly
UE - Gameplay - Jun 4, 2024The description of SpringArmComponent's "Use Camera Lag Substepping" option says "sub-step camera damping so that it handles fluctuating frame rates well". However, as noted and explained by a licen ...