Unreal Engine Issues
Unreal Engine Issues
[Material Substitution] Missing Material IDs in exported CSV in 2025.2
TM - Interoperability - Oct 7, 2025Reported in SF [Link Removed] When exporting material IDs in 2025.2, downloaded materials appear to be missing from the exported CSV. In 2025.2, it appears that only local materials are included i ...
20 FPS performance drop between 4.7.6 and 4.8 on devices rendering Metal only
UE - Platform - Mobile - Jun 22, 2015User reported a considerable performance drop on iOS between versions 4.7.6 and 4.8. I was able to reproduce this perf drop using the steps he provided. ...
After upgrading a project from 4.7 to 4.8 and compiling a blueprint that casts to and pulls a variable from a widget will cause a freeze if the widget is then compiled
UE - Gameplay - Blueprint - May 7, 2015If the user has a project that casts to a widget to pull out a variable in a 4.7 project. This can cause a freeze after upgrading the project to 4.8 preview. This happens when the user compile the b ...
Crash occurs when executing r.RHIThread.Enable 2 command
UE - Rendering - Architecture - RHI - Jan 19, 2023This is not a regression. Tested in //UE5/Release-5.0 CL20379098 Editor crashes with an assertion after executing the command r.RHIThread.Enable 2 ...
2 GB/hr Memory Leak on levels that are not enclosed
UE - Graphics Features - Feb 19, 20162 GB/hr Memory Leak on maps with no Sky Sphere or Atmospheric Fog to occlude empty space. The leak also occurs during general usage, but was tested with a blank project and an absolutely blank leve ...
Can Ever Affect Navigation Option Being Reset Upon PIE
UE - AI - Mar 29, 2016Upon PIE, the Can Ever Affect Navigation option is being reset on the capsule component of an empty character. Dragging the empty character into the level, setting the option to true, and then playi ...
Open Formats: Interchange Import Runtime - Interchange ImportAssetAsync runtime GLB import — materials, textures, tangents, and shaders non-functional in packaged builds (6 issues, UE 5.7.4)
UE - Editor - Open File Formats - Apr 30, 2026Description* We are using Interchange's `UInterchangeManager::ImportAssetAsync()` to import GLB files at runtime in a packaged (Shipping) application. The orchestration layer (`ImportInternal` in `In ...
In 5.7, a Sequencer that contains a Spawnable ChaosCacheManager will crash the Engine on EndPlay
UE - Simulation - Core - Nov 30, 2025In 5.7, a Sequencer that contains a Spawnable ChaosCacheManager will crash the Engine on EndPlay. The licensee has reported, and I've confirmed, that this behavior started in 5.7. I've confirmed thi ...
Translating bones in Persona is not affected by Snap Options
OLD - Anim - Dec 14, 2016In Persona, moving a socket around is not affected by any changes to snapping (scale or size). Rotation is affected however. This is similar to [Link Removed], but according to James Golding there ...
2 minute hang and high memory usage when adding assets with large textures
UE - Foundation - Core - Cooker - May 28, 20152 minute (or more) hang and high memory usage when adding assets with large textures. The memory increase can be up to 3 or 4 GB when none of these assets(or referenced assets) take up nearly that ...