Unreal Engine Issues
Unreal Engine Issues
Python crash the engine at exit.
UE - Editor - Workflow Systems - Oct 25, 2022A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...
Crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() when quickly unloading then loading a sub-world partition
UE - World Creation - Worldbuilding Tools - Data Layers - Mar 6, 2025From licensee: Since we integrated 5.5, we are experiencing a crash in AWorldDataLayers::InitializeDataLayerRuntimeStates() on this line check(ActiveDataLayerNames.IsEmpty() && LoadedDataLayerN ...
[CrashReport] UE4Editor_UMG!TBaseDelegate<FMargin>::operator=() [delegatesignatureimpl.inl:381]
UE - Editor - UI Systems - Aug 29, 2017This is a longstanding and common UMG crash that has affected more than 200 users since at least the 4.15 release. User DescriptionsI was working in the UI and undid several last changes in quick s ...
Simulated ability tasks not being cleaned up in UActorChannel::ReplicationMap
UE - Networking - Nov 20, 2018I've noticed the issue occurring in both 4.20.3 (CL 4369336) and 4.21.0 (CL 4541578). The user on AnswerHub has also noticed the issue in 4.20.2 (CL unknown) and claims the issue did not occur in 4. ...
Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant
UE - Gameplay - Player Movement - Feb 26, 2024When the character class is set to always relevant, if a client travels very far away from another character, such that the character is relevant but the component they're standing on is not (but al ...
PakFiles: Unmounting PakFile while requests are still in progress causes assertion failure in UnMount
UE - Foundation - Mar 31, 2022[Link Removed] Licensee is using the chunk downloader. On Shutdown method of their GameInstance, they call FChunkDownloader->Finalize. When they quit the game (Alt+F4) during a chunck download an a ...
Build failure after nativizing any child Blueprint class with function override (regression).
UE - Gameplay - Blueprint - Jun 7, 2018Nativization regression in 4.20 preview 1. Cannot nativize overridden functions. Log Output:UATHelper: Packaging (Windows (64-bit)): D:/Projects/Unreal/NativizeMethod/Intermediate/Plugins/Nativized ...
GetPackageLengthForCooking can be much larger than the actual file path length
Tools - Jul 10, 2019If the file path with the asset contains a project name, the cooking file pathlength is incorrectly increased. The following code in ContentBrowserUtils :: GetPackageLengthForCooking causes this is ...
Access Violation - UMovieSceneFolder::PostLoad - Accessing freed memory
UE - Anim - Sequencer - Sep 19, 2024A licensee has hit an access violation issue due to a movie scene containing a reference to an invalid child object binding. It triggers in the following method: UMovieSceneFolder::PostLoad // Vali ...
Player Controller does not handle multiple CharacterMovement movement modes
UE - Gameplay - Blueprint - Feb 6, 2018From Bug Submission: The variable in the image I attached is unable to distinguish between multiple characters all possessed by the same player controller. So if one character has this variable set ...