Unreal Engine Issues

Python crash the engine at exit.

A 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 ...

When duplicating the last point in a closed-loop spline, its metadata is inserted at the wrong index

The SplineComponentVisualizer allows users to alt+drag on a spline point to duplicate it. When this is done on the last point of a spline marked as "closed-loop", the new point is correctly added at ...

[CrashReport] Access violation - FBlueprintCompilationManagerImpl::ReinstanceBatch

This is a trending crash in the 4.17 Preview. Unfortunately users have not provided any additional information. There is no record of this crash occurring in 4.16.2, so it is possibly a regression. ...

WP HLOD Crash on Small Cell Sizes

[CrashReport] UE4Editor-MetalRHI.dylib!FMetalDeviceContext::CreateDeviceContext()

Error message: SEGV_MAPERR at 0x3 Source Context: Most recent user affected CL: 3249277 Logs: [Link Removed] [Link Removed] [Link Removed] [Link Removed] CrashReporter User Descriptions:Just i ...

Physics Substepping doesn't have the same effect from 4.15 to 4.16

Physics Substepping doesn't have the same effect from 4.15 to 4.16. In 4.16+ the ponytail in the provided project will have a jitter effect even with substepping enabled. This is a regression: Work ...

Simulated ability tasks not being cleaned up in UActorChannel::ReplicationMap

I'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. ...

No arm64 folder exists in plugins leading to an Error when packaging plugins

Regression: Checked in UE5/Release-5.0, the folder is missing from the plugin as well. This issue appears to be a problem with packaging the plugin itself, rather than packaging a full project. Pac ...

Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant

When 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

[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 ...