Unreal Engine Issues
Unreal Engine Issues
Material parameters flickering due to UMG animation switching and multi-threaded execution
UE - Editor - UI Systems - UMG - May 12, 2026When continuously transitioning to UMG animations that have a track targeting the same material parameter within the UUserWidget::OnAnimationFinished event, the number of source inputs to UMovieScen ...
UMG Widget color and Text color has different output at UE4 editor to Mobile preview and Mobile device.
UE - Editor - UI Systems - Jul 3, 2015UMG Widget color and Text color has different color output at UE4 editor to Mobile preview and Mobile device. https://udn.unrealengine.com/questions/251945/umg-viewport-device%E1%84%8B%E1%85%A6%E1% ...
ARCore plugin missing 'tools' components
UE - Platform - XR - Jul 28, 2018https://forums.unrealengine.com/development-discussion/vr-ar-development/1494917-ue-4-20p4-arcore-image-database-cannot-build/page2 Bo Pang from Google writes: "I think there are two issues here: 1 ...
RestrictedToClasses UCLASS Meta expects space delimiters but documentation shows comma delimiters
UE - Gameplay - Jul 19, 2019The documentation: https://docs.unrealengine.com/en-US/Programming/UnrealArchitecture/Reference/Metadata/index.html shows the RestrictedToClasses meta syntax as being RestrictedToClasses="Class1, C ...
When set the current language and asset group to different languages, the asset group will not work
UE - Editor - UI Systems - Localization - Nov 22, 2020When set the current asset group language in a particular process, the asset refers to the "source asset" and output warning log. LogPackageLocalizationCache: Warning: Skipping the cache update for ...
Hardware Lumen Surface Cache Artifacts on Nanite Geometry
UE - Graphics Features - Lumen - Sep 1, 2025When using Hardware Lumen with Nanite-enabled meshes in UE 5.6+, black / dark surface cache artifacts appear that result in generally darker and unstable lighting. These artifacts are not immediatel ...
Actors unrelated to the changelist being validated cause errors
UE - World Creation - Worldbuilding Tools - World Partition - Nov 22, 2023When validating a changelist, unrelated errors to the changelist can appear. Here's an example of running the validation on a cl named "temp cl" which just contains a single actor "Cylinder". The A ...
[CrashReport] UE4Editor_Core!FWindowsWindow::Initialize() [windowswindow.cpp:199]
Tools - Mar 1, 2017Error message: Assertion failed: 0 [Link Removed] [Line: 199] Window Creation Failed (1158) Source Context: 184 VirtualHeight = ClientHeight; 185 186 // We call reshape w ...
Blueprint Projects can't make APK without compiled .so Error when packaging for Android with any Plugin Disabled
UE - Platform - Mobile - Sep 5, 2018Blueprint Projects can't make APK without compiled .so Error when packaging for Android with any Plugin Disabled. Also seeing Gradle errors if SteamVR plugin is disabled. Setting min version to 14 ...
In class UCancellableAsyncAction, methods IsRegistered() and ShouldBroadcastDelegates() still return true after Cancel() or SetReadyToDestroy() unregisters the object.
UE - Framework - Blueprint - Jun 26, 2024Class UBlueprintAsyncActionBase provides methods RegisterWithGameInstance() and SetReadyToDestroy(), which respectively register and unregister the object with the game instance. Derived class UCanc ...