Unreal Engine Issues
Unreal Engine Issues
Using GeoMerge on fragments of a GeometryCollection (GC) will create a new single particle while removing the old particles, but although you end up with less particles, the disk file size of the GC uasset increases.
UE - Simulation - Physics - Destruction - Nov 26, 2024Using GeoMerge on fragments of a GeometryCollection (GC) will create a new single particle while removing the old particles, but although you end up with less particles, the disk file size of the GC ...
Crash undoing variable change in Animation Blueprint.
OLD - Anim - Aug 1, 2016Crash occurs when the user changes a variable in the animation blueprint, and then undo's the change. Note that this occurs with any variable being used, but the callstack will be some what differe ...
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.
UE - World Creation - Worldbuilding Tools - World Partition - Aug 19, 2025Context 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 ...
SteamVR turns off vsync globally
UE - Platform - XR - Feb 21, 2020Additional Info From User: Result: Vsync will get turned off by FSteamVRHMD::Startup() setting a global console variable, regardless of your project configuration. Expected: Vsync is only deacti ...
Swapping between Multiple Cloth Skeletal Meshes and Animation Classes in a Character Blueprint causes the Engine to crash
UE - Simulation - Physics - Aug 2, 2018When changing Cloth Skeletal Meshes and Animation Blueprints on a Character it will cause the Engine to crash during PIE. This is a regression from 4.19.2 (CL-4033788) as it was working as expected ...
Low-level memory tracking has negative values for "FMallocUnused" and "Untracked"
UE - Foundation - Core - Oct 6, 2020"FMallocUnused" is immediately bellow 0. "Untracked" is reported to go below 0 after very long playtimes (over 36 hours). Reported in version 4.25.3(CL 13942748). Tested and found negative values f ...
[CrashReport][Assert] UnrealEditor-RHI!FRHIResource::MarkForDelete() [Engine/Source/Runtime/RHI/Private/RHIResources.cpp:49]
UE - Rendering Architecture - Materials - Dec 18, 2024One of the users described this issue as below. "At seemingly random times while working in the material graph, some action will cause a hitch or freeze, and quickly after the engine will crash, an ...
Bloom intensity broken with Post Processing Material replacing Tonemapper
UE - Graphics Features - Sep 25, 2020When replacing the Tonemap using a Post Process material, the Post Process Volume's Bloom Intensity can only be turned on or off, without varying degrees of effect. Reported in version 4.25.3(CL 1 ...
IAP failed to read purchase
UE - Platform - Mobile - Feb 20, 2017In-app purchases do not seem to be working properly in Unreal Match 3 or other games ...
Soft angular constraints solve velocity like hard constraints
UE - Simulation - Core - Jul 17, 2025Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...