Unreal Engine Issues
Unreal Engine Issues
Spline Mesh regression on older iOS phone
UE - Platform - Mobile - Jun 10, 2019Regression with rendering Spline Mesh Components seen on older (5s) iOS device. I did not reproduce a crash with an iPadPro A1701 or an Android Note 4 Confirmed in 4.23 MAIN at CL 6910902 ...
NiagaraSystem is compiled every time when first loaded in the editor
UE - Niagara - May 20, 2022If you are using a large amount of Niagara, you will experience excessive load times in PIE even if nothing is changed. The following code change seems to be effective as an interim response. void ...
When moving actors to the current level, their label is reset and displayed incorrectly on the Scene Outliner until the next time it is refreshed
UE - Editor - Workflow Systems - Jul 14, 2025This is a regression, it worked correctly up to UE 5.4, but repros on UE 5.5 and 5.6. Also, this seems related to [Link Removed], which was fixed by CL 40649716/40649749 and integrated into UE 5.6, ...
Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior
UE - Simulation - Physics - Nov 21, 2024Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior. In the repro project provided (see addl in ...
Visible dithered quantization to remove banding in New Temporal AA Quality
UE - Graphics Features - Oct 6, 2015Since changing the temporal history buffer to 11:11:10 from FP16, it looks as there is visible dithered quantization to remove banding when rendering. (Taken from conversation on Forum Post linked f ...
ACineCameraAttachMount's "Target Actor" constraint does not work with Spawnables or Replaceables in Sequencer
UE - Virtual Production - Tools - Virtual Camera - Aug 12, 2025Constraints (UTickableConstraint) are usually created throuh the "Animation" tab available in the Editor's "Animation Mode". When created through that interface while Sequencer is open, the internal ...
Bug in StringTemplate.cpp related to modulo operator in MaterialTemplate.ush (code fix provided)
UE - Rendering Architecture - Materials - Jun 25, 2024Shader Template files like MaterialTemplate.ush do not submit previous chunks when encountering a `%` character, unless that `%` character is `%s` or `% {...} `. Because the error is happening ...
check(!bPostTickComponentUpdate) fails triggered by ~FStaticMeshComponentBulkReregisterContext() and FD3D12DynamicRHI::ProcessInterruptQueueUntil()
UE - Gameplay - Components - Jul 23, 2024Context: Some ActorComponents can schedule end-of-frame work which UWorld executes later in the frame in UWorld::SendAllEndOfFrameUpdates(). By-design it appears that it's not allowed to schedule mo ...
Linux crash upon opening maps in Soul: City content pack
UE - Graphics Features - Jan 29, 2018Opening the maps from the Soul: City asset pack on Linux causes a crash. This seems to be rendering related. It was originally reported as a Vulkan specific issue but we've reproduced it without Vul ...
Unable to change Actor Coloration View Modes in PIE
UE - World Creation - Worldbuilding Tools - Jul 20, 2025When in PIE changing Actor Coloration view modes from the viewport visualisation mode [Liit] -> [Actor Coloration] -> ... Does not update correctly when switching view mode and sometimes isn't corr ...