Unreal Engine Issues
Unreal Engine Issues
World Memory Leaks crash with a hidden sublevel to a redirector
Tools - Dec 8, 2020From UDN: The reason it crashes is because Child doesn't get garbage collected, which is because it still has the RF_Standalone flag. UEditorEngine::EditorDestroyWorld clears RF_Standalone flag ...
Mutable: Child parameters hidden when intermediate Object Group uses "All Options"
UE - Runtime - Mutable - Mar 31, 2026FCustomizableInstanceDetails::FillChildrenMap() unconditionally registers parent-child relationships via __ParentParamName metadata without verifying the parent exists in the active parameter list. ...
[CrashReport] UE4Editor_UnrealEd!FBlueprintEditorUtils::FindBlueprintForGraphChecked() [blueprinteditorutils.cpp:2206]
UE - Gameplay - Blueprint - Aug 29, 2017This is an infrequent crash coming out of the 4.17 release. Users have not provided any descriptions of their actions when the crash occurred. Source Context 2200 // Helper function to get ...
[CrashReport] Ran out of memory - FFixedUObjectArray::PreAllocate()
UE - Foundation - Core - UObject - Sep 7, 2017This is a somewhat common crash affecting users in 4.17. Users have not provided any descriptions of their actions when the crash occurred. Source Context 165 if (GWarn) 166 { ...
Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity
UE - Rendering - 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 ...
Linux: Assertion at splash screen when trying to open UE4Editor
UE - Platform - Linux - Mar 21, 2017I ran into this while looking to verify [Link Removed] at CL 3355923. I logged the issue I was verifying the fix for last night and have not updated anything locally, so the "OpenGL 4.3 not supporte ...
[CrashReport] UE4Editor_MovieSceneTracks!UMovieSceneCameraCutSection::GenerateTemplate() [moviescenecameracutsection.cpp:24]
UE - Anim - Sequencer - Oct 30, 2017This is a somewhat common Sequencer crash that occurs in 4.17 and 4.18. User DescriptionsWas trying to copy and paste a camera movement but something screwed up, I tried to add an already built Cam ...
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 ...