Unreal Engine Issues
Unreal Engine Issues
[CrashReport] UE4Editor_SlateCore!SWidget::SlatePrepass() [swidget.cpp:493]
Tools - Dec 1, 2017This is a common crash in the 4.18 release. The callstack is rather generic, and I have attached two logs but neither displays the error information. Users have also not provided any descriptions ...
When using Perforce, saving a level over another leaves the target umap file as "marked for delete"
UE - Editor - Workflow Systems - Mar 11, 2025When working on a level asset and using command "File – Save Current Level As..." to save it over a different level asset, the engine first deletes the target level (that's going to be overwritten) ...
Crash Occurring in FD3D11DynamicRHIModule::FindAdapter()
UE - Graphics Features - Jul 13, 2016Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 804] Array index out of bounds: 1 from an array of size 1 Source Context: 352 353 // We a ...
[CrashReport] UE4Editor_Engine!FShaderCompilingManager::LaunchWorker() [shadercompiler.cpp:1573]
UE - Graphics Features - Aug 21, 2017This is a common and longstanding crash that has occurred since at least 4.9. The issue appears to be due to missing ShaderCompileWorker.exe in binaries, but many of these crashes occur in the vani ...
Virtual texture thumbnails appears brighter (incorrect sRGB/gamma) in content browser after asset is loaded
UE - Editor - Dec 9, 2025This is a regression, it worked correctly up to UE 5.5 but behaves incorrectly in UE 5.6 up to latest. When a regular texture with sRGB enabled is converted to a virtual texture, its thumbnail in t ...
Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor
UE - Anim - Anim in Engine - Jul 15, 2025Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...
Blueprint fails to compile when adding new member to struct that is an input parameter of implemented interface function
UE - Gameplay - Blueprint - Jun 3, 2016Adding variables to a structure that is an input parameter of an interface function causes a compile error in any blueprint that implements the interface until the interface is recompiled. Compile ...
Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA
UE - Rendering - Graphics Features - Feb 5, 2025There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...
UPlacementSubsystem does not respect AssetFactories priorities, which is inconsistent with UEditorEngine::ActorFactories and makes it impossible to override placed actor type when dragging asset from Content Browser to Level Editor Viewport.
UE - Editor - Workflow Systems - Mar 30, 2026Note: This issue was reproduced in UE 5.7, and it works correctly in UE 4.27. Prior to CL 24938100 (between UE 5.1 and 5.2), all existing factories were discovered and registered during engine init ...
Crash rendering image sequence if the Sub-Level with matinee is not loaded
Tools - Apr 15, 2016Crash rendering image sequence if the Sub-Level containing the matinee is not loaded. This seems to go away if the level is either set to "Always Loaded". Seems to be a result of people not switch ...