Unreal Engine Issues
Unreal Engine Issues
FileSystemDerivedDataBackend may output a corrupted access log
UE - Foundation - Core - Derived Data - May 20, 2021This problem is caused by the AccessLogWriter has not been flushed at the termination. The following workaround flushes the Writer.class FFileSystemDerivedDataBackend : public FDerivedDataBackendInt ...
Crash when a Deferred Decal (Translucent) base material has a Nanite Override (Masked Surface) Material and the mesh has Nanite + Ray Tracing enabled.
UE - Graphics Features - Ray Tracing - Aug 14, 2025A crash occurs when Nanite override material instance is used in a project with Ray tracing enabled where: 1 The Material assigned to the static mesh uses Deferred Decal / Translucent and the Nani ...
Collision channel settings are not recognized in Standalone
OLD - Anim - Oct 18, 2017Object instances that override the parent blueprint's collision settings are recognized in PIE but ignored in standalone or when running from the command line with -game NOTE: This appears to only ...
The 'Set Constrained Components' node doesn't set the physics constraint components correctly if used in the Construction Script
UE - Simulation - Physics - Jan 20, 2015The 'Set Constrained Components' node doesn't set the physics constraint components correctly if used in the Construction Script. ...
Environment Query System (EQS): EnvQuery runtime template object can be created with a non-unique name, corrupting the EnvQueryManager cache
UE - AI - Aug 5, 2025On file [Engine\Source\Runtime\AIModule\Private\EnvironmentQuery\EnvQueryManager.cpp:812], function UEnvQueryManager::CreateQueryInstance() uses StaticDuplicateObject() to create a new UEnvQuery* (d ...
Blueprint enum-to-string node returning inconsistent results across platforms
UE - Gameplay - Mar 5, 2020Converting a C++ enum to a string should be a consistent result, however when running in the editor it returns the display-name value instead of the index value. This prevents C++ UENUMs from being ...
A crash can occur when multiple Actors are spawned/destroyed simultaneously with each one loading an asset.
UE - Foundation - Core - Jan 6, 2017A crash can occur if multiple Actors are spawned/destroyed simultaneously, with each Actor loading an asset when it is spawned. This does not occur 100% of the time, but it does occur quite frequent ...
The Sorting Issue Between Height Fog and Transparent Objects
UE - Graphics Features - Aug 21, 2024When a LocalFogVolume is used with ExponentialHeightFog, it does not correctly fog translucent objects. ExponentialHeightFog and Volumetric Fog from a LocalFogVolume both correctly occlude transluc ...
Any Alpha value set in a FLinearColor used to draw a line on a Canvas HUD is ignored when the line is drawn
UE - Graphics Features - Apr 21, 2015If an Alpha value is set in a FLinearColor that is used to draw a line on a Canvas HUD, the Alpha value is ignored when the line is drawn. A comment in BatchedElements.cpp indicates that some legac ...
Hot reload fails in 4.16 projects that were upgraded from 4.15.
UE - Foundation - Cpp Tools - Hot Reload - May 16, 2017This issue appears to be a continuation of [Link Removed]. Hot reloads work successfully in projects that were created in 4.15 or 4.16 and are still using the same Engine version that they were crea ...