Unreal Engine Issues
Unreal Engine Issues
Creating FTickableObjectBase inherited class in async thread may cause pure virtual function call
UE - Framework - May 22, 2025Classes that inherit from FTickableObjectBase are added to the tickable queue by the QueueTickableObjectForAdd function during their construction (see FTickableGameObject::FTickableGameObject). At t ...
[AI] SmartObjectSlot does not have a valid node ref even when it should project to navigation.
UE - AI - SmartObject - May 17, 2025If you request a SmartObject slot entrance location and require it to be navigable, it will return a result that does not include the node ref of the nav poly for the entrance to the slot. Instead i ...
Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level
UE - Foundation - May 15, 2025In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...
Editor 'Build All Levels' discards Volumetrics Lightmaps in persistent level
UE - Graphics Features - May 14, 2025Building the level or lightmaps can clear the volumetric lightmap. In 5.5, this requires you to perform a full build, or a lighting only build with a BSP brush in the scene. In 5.6, all level build ...
ResavePackages commandlet (buildlighting) fails/asserts on reflection captures in non-visible sub-levels
UE - Graphics Features - May 13, 2025When building reflection captures through the ResavePackages commandlet, it frequently triggers an ensure inside of ReflectionEnvironmentCapture.cpp. If distributed shader builds start causing prob ...
PIE Seamless Travel with a standalone level instance causes assert in UWorldPartition::BeginDestroy
UE - World Creation - Worldbuilding Tools - Level Instances - May 8, 2025This check is hit on the server instance while it is performing garbage collection during the seamless travel. During this garbage collection, it will determine that the UWorldPartition object belon ...
Mover character flickers downward while crouched and moving every so often
UE - Gameplay - Player Movement - Mover - May 8, 2025Repro Rate 5/5 Packaged onWindows - 10 - Enterprise - L3864 Processor: AMD Ryzen Threadripper PRO 3975WX 32-Cores 3.50 GHz RAM: 128 GB GPU: NVIDIA GeForce RTX 3080 GPU Driver Version: 572.83 ...
Actor Channel failure occurs when quickly unloading and loading a streaming level
UE - Networking - May 8, 2025With high enough latency, quickly unloading an reloading a streaming level with a replicated actor on the server can cause the actor channel on the client to fail to find this actor: UActorChannel:: ...
Assertion failed in FNetGUIDCache::CleanReferences during seamless travel after reloading primary asset package
UE - Networking - May 7, 2025Following this sequence of events, the ObjectLookup and NetGUIDLookup on the server's PackageMapClient will end up in a bad state. In the ObjectLookup Map, the primary asset's package will be mapped ...
AssetRegistry: In a packaged game ScanPathsSynchronous with bForceRescan=true will permanently forget about assets inside IOStore containers
UE - Foundation - Data Pipeline - May 7, 2025This came up from several discussions on UDN and internal discussion. The root cause is that the AssetRegistry currently cannot discover packages inside IOStore containers, it relies on the seriali ...