Unreal Engine Issues

Cook non-determinism when serializing UObject pointers pointing to garbage

There's a cook determinism issue in the way UObject unversioned serialization handles UObject pointers pointing to garbage. Depending on GC timing, it can either be skipped (as a property matching C ...

"Detaching from existing linker" error messages when running Fixup Redirectors commandlet

MRQ rendering crashes when there is an empty audio track

Heterogeneous Volume Actor causes ensures to trigger in Debug builds

When a heterogeneous volume actor is used with a volume material in a debug build, the following ensures are triggered: Ensure condition failed: UniformBufferValue || EnumHasAnyFlags(AutomaticallyBo ...

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Slow editor/PIE loading of UWorldPartitionHLODSourceActorsFromCell

Loading UWorldPartitionHLODSourceActorsFromCell takes a lot of time in editor + PIE when it contains a lot of actors per UWorldPartitionHLODSourceActorsFromCell (between 2K and 2K actors). ...

Slate text layout AllowPerCharacterWrapping issue

Customer-reported bug in TextLayout (AllowPerCharacterWrapping): Issue seems tied to bHasTrailingText handling in TextLayout.cpp (~line 694). The remainder handling after wrap inserts an extra break ...

Missing PSO Precaches in the engine

A licensee wanted to report some missing PSO Precaching they found, which they have fixed locally: 1. UCableComponent doesn't implement CollectPSOPrecacheData or call CheckPSOPrecachingAndBoostPri ...

Physics Mover: AI movement and collisions can cause sharp increase in velocity

A pawn using the physics mover and using AI movement can sometimes gain an ton of velocity quickly upon colliding with another physics object. It seems to fix it self and revert back to it's origina ...

Sub-world partitions do not properly handle partial editor loading as world partition standalone level instances' spatially loaded actors do not get loaded even when the Level Instance is force loaded or loaded in by region.

Context Level Instancing is a level-based workflow designed to improve and streamline the level editing experience. In a standalone Level Behavior, when the Level Instance Actor is loaded through it ...