Unreal Engine Issues
Unreal Engine Issues
Regression for UPROPERTY specifier causing crash ("Template Mismatch during attachment") during PIE
UE - Foundation - Core - Jun 19, 2015If the UPROPERTY() specifier "VisibleDefaultsOnly" or "EditDefaultsOnly" is used on a component reference that is attached to the root component selecting the actor with this component in the world ...
Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity
UE - Graphics Features - Nov 27, 2025Note that this bug potentially also affects a wide variety of material / geometry setups; however, a translucent wireframe setup is currently the main reproduction case. The issue may also be notice ...
GameInstance and subsystem initialization order is incorrect for Play In Editor
UE - Gameplay - May 18, 2023The order of world and game instance initialization is different between a true standalone game (cooked game or an editor build with -game) and a Play In Editor game. Specifically, in Play in Editor ...
Event Dispatcher not being called in 4.6
UE - Gameplay - Blueprint - Dec 8, 2014ED nodes in 4.6 but are not being executed in standalone or cooked games. Also, users receive compile errors when the project is saved and reopened that resolve when the blueprint is recompiled. ...
Navigation does not work in sub-levels
UE - AI - Jan 28, 2015Navigation does not work in sub-levels. If the Nav Mesh Bounds Volume in a sub level is not touching a Nav Mesh Bounds Volume in the Persistent Level, it will not appear or function during Play. It ...
TargetArray nodes are reported as invalid if played in Standalone mode but not in PIE
UE - Gameplay - Blueprint - Feb 20, 2015TargetArray nodes are reported as invalid if played in Standalone mode and the blueprints they are contained in are not rendered. Playing in PIE however works correctly and all blueprints are rende ...
Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5
UE - Framework - LWC - Jan 15, 2024FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...
Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key causes a memory leak
UE - Framework - Blueprint - Apr 15, 2025When Calling UBlueprintMapLibrary::GenericMap_Find with a non-existent key, the function construct the default structure in-place on the given pointer without destroying the object. This behavior ca ...
Fail to compile with Added AIController class
UE - Foundation - Core - Jan 14, 2015User fails to compile code template after adding AIController code to project. Regression: Not a regression happens in 4.6.1 CL-2386410 Setting up Mono Building MyProjectEditor... Compiling game m ...
[AI] Debug Render Scene Proxy hits ensure for registering a delegate twice during level streaming.
UE - AI - Debugging - Aug 31, 2022Description from licensee: We're seeing an ensure get tripped up in FDebugRenderSceneProxy that says "DrawDelegate is already Registered!". Debugging the issue, we have confirmed that the DrawDeleg ...