Unreal Engine Issues
Unreal Engine Issues
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 ...
Assertion fails when a struct is opened with a BP class reference stored and with that struct as a variable in the BP class that's referenced.
UE - Gameplay - Blueprint - May 10, 2022Assertion fails when a struct is opened with a class reference stored and with the struct as a variable in the class that's referenced. A restart is required in order to see this occur. Repro Rate: ...
Arrays chosen through a Select node cannot be altered
UE - Gameplay - Blueprint - Jun 3, 2015Arrays chosen through a Select node cannot be altered. Note - This is also reproducible using any of these nodes instead of using 'Add':Add UniqueSet Array ElemInsert ...
Crash occurs while replacing a Widget Component with a user created Text Block
UE - Editor - UI Systems - UMG - Aug 18, 2022This is not a regression. Tested in //UE4/Release-4.27 CL18319896. The crash occurred. Crash occurs while replacing a Widget Component with a user created Text Block blueprint. ...
Editor ensure in USceneComponent::OnComponentDestroyed during Blueprint compilation GC
UE - Framework - Components - Jan 15, 2026An editor-only ensure can trigger during BP compilation when garbage collection cleans up transient components created as part of component replacement. During recompilation, old component instances ...
'Set Playback Position' node fires Timeline event even if 'Fire Events' is set to false
UE - Gameplay - Apr 30, 2015'Set Playback Position' node fires Timeline event even if 'Fire Events' is set to false. User Description: Basically using the set playback position node to set a new time position for a timeline ...
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 ...
Destructing NiagaraParameterStores causes multi threading write conflict
UE - Niagara - Jan 26, 2022FNiagaraParameterStore::UnbindAll() may be called from both GameThread and RenderingThread. Each may modify the same Binding array, it causes infrequent crashes. In my environment, I was able to r ...
PhysX generates extra "sleep" event when moving Kinematic actors away from Simulated actors with Teleport option.
UE - Simulation - Physics - Aug 4, 2016Issue seems to be related to NpRigidDynamic::setKinematicTarget. When called by itself (like in the case of Kinematic bodies moved without teleportation), the simulated actor is woken and is put ba ...
Cannot save actor after actor component modification, Graph is linked to private object(s) in an external package
UE - Gameplay - Blueprint - Sep 28, 2016Cannot save actor after actor component modification. The user gets the error Graph is linked to private object(s) in an external package ...