Unreal Engine Issues
Unreal Engine Issues
Sequencer frame range progression is not continuous
zComponent - Archive - Oct 28, 2021The end of the level visibility section places a DeterminismFence. This causes the issue. The fence clips the frame range and produces a discontinuous frame ranges, e.g. 23201~24000, then 24001~24 ...
Open Formats: Reimport PIE - Reimporting an asset during PIE overwrites the bAllowCPUAccess value to true
UE - Editor - Content Pipeline - Import and Export - May 22, 2025When reimporting a static mesh asset before PIE execution, the value of bAllowCPUAccess is false. If reimporting a static mesh asset while PIE is running, the value of bAllowCPUAccess is true. In a ...
Camera behavior during "Orbit Pan Mode" (Alt+MMB+Drag) is wrong while piloting an actor
UE - Editor - Nov 18, 2025In the Level Editor, dragging the mouse while the "Alt" key is pressed performs one of the "Orbit" movements: OrbitRotation, OrbitPan, OrbitZoom. The same can be done while Piloting an actor. Howev ...
Crash in GC - FSharedStruct reachability race condition
UE - Core - Systems - Jul 13, 2026This Jira was created from the linked EPS case: =============================================== This issue is caused by FSharedStruct batching reachability requests to the same underlying FInstan ...
[CrashReport] UE4Editor-Core.dylib!FTextHistory::Rebuild(TSharedRef<FString,()
UE - Platform - Apple - Aug 15, 2017This is a trending Mac crash in 4.17.0 that has also occurred with some frequency since at least 4.14. I have not been able to identify any matching callstack occurring on Windows, although it does ...
VerboseCookerWarning warnings: Saving object into cooked package %s which was created at cook time, Object Name UniqueObjectNameForCooking_0, Full Path %s, Outer class %s
UE - Core - Data Pipeline - Cooker - Jun 19, 2023Creating objects at cook time that are exported into the cooked package is a possible cause of indeterminism, and therefore we have banned it in engine classes and will fire a warning about it. Cur ...
Editor Crashes when attempting to copy/paste nodes in Material Editor
UE - Graphics Features - Nov 18, 2014UPDATE: 1/8/2015 Crash Reporter: [Link Removed] Callstack: <unknown module>! KERNELBASE!RaiseException() <unknown module>! UE4Editor_Core!FOutputDeviceWindowsError::Serialize() <unknown module> ...
Level Instance Property Override: Actor::Tags overridden pre-CS but clobbered by RerunConstructionScripts with no post-CS re-apply
UE - World Creation - Worldbuilding Tools - May 4, 2026Summary When using the Level Instance Property Override system, overrides applied to `AActor::Tags` are silently lost for Blueprint actors whose Construction Script assigns or appends to `Tags`. The ...
Clicking the Add Variable button in a Struct that is referenced as two inputs in a function that is called in an Actor Blueprint's Construction Script causes a crash
UE - Gameplay - Blueprint - Jun 28, 2015Clicking the Add Variable button in a Struct that is referenced as two inputs in a function that is called in an Actor Blueprint's Construction Script causes a crash. This does not occur in the Even ...
[CrashReport] UE4Editor-ApplicationCore.dylib!FMacWindow::ApplySizeAndModeChanges()
UE - Platform - Apple - Oct 27, 2017This is an early trending Mac crash in 4.18. Users have not provided any descriptions of their actions when the crash occurred. Callstack from LogLogAssetRegistry: Asset discovery search completed ...