Unreal Engine Issues
Unreal Engine Issues
Colon in UPROPERTY category invalidates iterative build
UE - Foundation - Core - Cooker - Jan 13, 2017The presence of a colon ':' character in the category string of a UPROPERTY will cause iterative cooking to generate the following error:Found unparsable ini setting Windows.EditorPerProjectUserSett ...
Saving Level changes the Rotation of actors with parent-child relationships
UE - Gameplay - Components - Nov 14, 2019According to the licensee report, UnrealMath.cpp (588) constfloat SINGULARITY_THRESHOLD = 0.4999995f; It seems that this can be avoided by changing the above value. However, changing SINGU ...
[AI] Failed check in UMassSpawnerSubsystem::DestroyEntities due to EntityManager still procesing
UE - AI - Mass - Sep 7, 2025It crashed when unspawning an AI which will destroy its entity. Inside DestroyEntities "IsProcessing" is true, but when it breaks into the debugger, "ProcessingScopeCount" is 0 (so IsProcessing shou ...
Toggling visibility of Sublevels on a server can cause a disconnect if Dynamic Actors exist in the sublevels.
UE - Networking - Aug 17, 2018The PackageMap / NetGuidCache appear to get into a bad state on Clients if the Server toggles level visibility of a sublevel. This can affect currently connected clients, as well as clients that jo ...
Request for 'Switch on Int' nodes to throw a warning or auto refresh if an execute pin is removed
UE - Gameplay - Blueprint - Nov 17, 2016Request for 'Switch on Int' nodes to throw a warning or auto refresh if an execute pin is removed. For example: If the 0 pin is deleted, users may not realize the pins will reset back to (0,1,2,3,e ...
Editing and committing changes to a PackedLevelActor Blueprint results in a crash
UE - World Creation - Worldbuilding Tools - Level Instances - Apr 5, 2022Repro Ratio: 3/3 Regression was tested in //UE5/Release-5.0-EarlyAccess CL-16682836 since this is a new feature of UE5. The issue did happen ...
[CrashReport] UE4Editor_Engine!FSoundConcurrencyManager::RemoveActiveSound() [soundconcurrency.cpp:545]
UE - Audio - Oct 5, 2017This is a common crash that has occurred since at least 4.15. The callstack is similar to [Link Removed], which was resolved in 4.16. User Descriptionsdisable sound concurrency Source Context 5 ...
Sequencer crashes when scrubbing characters with sub-anim instances and montage slots
OLD - Anim - Oct 2, 2019I saw a following assertion. Assertion failed: (AdditivePoses.Num() > 0) || (NonAdditivePoses.Num() > 0) [Link Removed] [Line: 1381] This is my quick fix// code placeholder void FAnimInstance ...
When r.SSR.Stencil is enabled, there is wrong logic observed.
UE - Rendering - Graphics Features - Dec 19, 2025When r.SSR.Stencil is enabled, the areas with high roughnesss are not discarded and Unlit materials are incorrectly handled. See the linked EPS case (Additional Info URL) for a full explanation of ...
Movie Render Queue Renders Black Frames when MultiSample Effects Are Disabled
UE - Anim - Sequencer - MRQ - Apr 25, 2022Occurs 5/5 times. When 'Disable Multisampling Effect' is enabled, the Render Warm Up is set to 0, and the Custom Playback Range is set to a small value, frames render out fully black. Regression d ...