Unreal Engine Issues
Unreal Engine Issues
Wrong WPO motion vectors due to Periodic World Space node
UE - Rendering - Graphics Features - May 13, 2026We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...
Crash after creating a suboject for RootComponent if the actor is placed on the level
UE - Foundation - Cpp Tools - Hot Reload - Nov 6, 2020The crash occurs when trying to assign a new value to RootComponent if the Pawn is already placed on the level Crash does not happen in P4 //UE4/Release-4.25.3 CL 13942748 Other steps to reproduc ...
Crash in Skeletal Editor due to null ActorFactory reference
OLD - Anim - Feb 1, 2017When a material is dragged/dropped into a skeletal editor's bone hierarchy, the editor will crash due to null ActorFactory Regression: Yes - Crash does not occur in 4.13.2 binary (CL 3172292) ...
[CrashReport] UE4Editor_Engine!LoadSpecialMaterial() [unrealengine.cpp:1523]
UE - Graphics Features - Nov 10, 2017This is a longstanding crash that has occurred for more than 200 users since at least 4.13. Based on user descriptions this appears to permanently corrupt a project. User DescriptionsI just turned ...
[CrashReport] UE4Editor_CoreUObject!UObjectPropertyBase::Identical() [propertybaseobject.cpp:60]
UE - Foundation - Cpp Tools - Hot Reload - Nov 17, 2016This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Error message: Access violation - code c0000005 (first/second chance not available) Source C ...
User-defined InstancedStaticMeshComponent subclass misbehave in SCS Editor
UE - Framework - Blueprint Editor - Oct 13, 2025Context Users can create InstancedStaticMeshComponent (ISMC) (blueprint) subclasses. Any ISMC class can be added to an actor blueprint. When a mesh is selected and transforms are added to the Insta ...
Unfocused Standalone window has reduced performance
UE - Rendering - Architecture - RHI - Aug 25, 2020User description: When I run two windowed standalone instances to test multiplayer, the unfocused window gets about 2-5 fps...but if I focus on it, smooth 120fps, yet the opposite screen is now onl ...
Crash when a subsystem calls GetSubsystemArray() on its owner while engine code is iterating on subsystems also obtained through GetSubsystemArray()
UE - Gameplay - Aug 6, 2024In some occasions, engine code iterates over a certain subsystem type by calling FSubsystemCollection::GetSubsystemArray() and then calling some method on all subsystems of the returned array. This ...
Backwards-compatibility broken for the CDOs of Python-generated Unreal Types because of missing redirectors
UE - Editor - Feb 11, 2025Previously, all Unreal Types generated by python scripts would be created inside package "/Engine/PythonTypes". This was changed by [CL 32478991 in ue5-main branch], which meant to "remove the restr ...
Crash when pressing Ctrl-Z after creating a blueprint function
UE - Gameplay - Blueprint - Feb 20, 2017Crash when pressing Ctrl-Z after creating a blueprint function *This is a regression: Working in 4.14.3-3249277 Not working in 4.15.0-3299760* Crash Reporter: Error message: Access violation ...