Unreal Engine Issues

Crash caused by Buffer Overread in TBitArray operator < function

A licensee has reported a crash that is caused by a Buffer Overread in TBitArray's operator < function. While the licensee did not provide reproduction steps, the crash is apparent from looking at t ...

After loading a SubLevel from the PersistentLevel of WorldComposition, the offset of WorldComposition is applied when loading the SubLevel alone

When loading a Sub Level from the Persistent Level of World Composition, the offset of WorldComposition is applied when loading the Sub Level by itself. The offset can be applied repeatedly when rel ...

Modifying collision shapes on a Skeletal Mesh with multiple cloth assets crashes

For skeletal meshes with multiple cloth assets in use, modifying any of the bone's collision body setup in the physics asset causes a crash.  ...

Actors in TMap Blueprint Properties are not copied properly for PIE

Actors that reside in TMap blueprint variables refer to the Editor actors not the copied UEDPIE actors (that we'd expect) when accessed in PIE. This is not the case in standalone; this only occurs f ...

Undo Crash with Reroute node into Class pin of SpawnActorFromClass

Crash on undo with SpawnActor node that uses a reroute pin in class wire. "It looks like the variable promotion marks the blueprint as structurally modified, which triggers a skeleton compile, wh ...

Logs containing UTF-8 characters don't appear in CMD/Terminal on Linux

If a log message contains UTF-8 characters like "ő" or any Russian one ("л") it won't be printed to cmd or terminal but it will be printed to the log file. This is a regression from 4.19.2 (CL-40337 ...

Custom node with SceneTextureLookup function doesn't support on Mobile anymore

Component default data can be lost for a non-nativized Blueprint class that inherits the component from a nativized parent Blueprint class.

This is a regression that was introduced by the fix for [Link Removed]. The fix makes an invalid assumption that instances of components whose archetypes are inherited by a non-nativized child Blue ...

Large UMG Blueprint widget trees can lead to very long compile times when packaging with Blueprint nativization enabled.

Licensee reports very long C++ compile times during packaging after nativizing a UMG Blueprint asset containing a very large and heavily-nested widget animation hierarchy. The support thread outlin ...

Volumetric Lightmap Holes Appear Every Fifth Build

Volumetric lightmap holes appear every fifth build.  Found in 4.19 CL# 4033788, 4.20 CL# 4302132, and 4.21 CL# 4348893 ...