Unreal Engine Issues
Unreal Engine Issues
Adding a widget to a grid panel inside the grid panel tick can cause an out-of-bounds error
UE - Editor - UI Systems - Slate - Jan 25, 2021This is caused by adding an item to a grid panel inside the grid panel iteration loop. The same operation to canvas panel goes well without any errors. The difference is that the array iteration in ...
Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity
UE - Rendering - 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 ...
[CrashReport] UE4Editor_SlateCore!IsResourceObjectValid() [drawelements.cpp:23]
Tools - Aug 2, 2018No user comments in crash group 18 FSlateShaderResourceManager* FSlateDataPayload::ResourceManager; 19 20 static bool IsResourceObjectValid(UObject*& InObject) 21 ...
editor crashes when variable inside of a struct is set to a class type then the object is moved to a new folder
UE - Gameplay - Blueprint - Mar 17, 2015If a struct has a variable set to a class type, then the object of that class type is moved to a new folder in the editor, the struct will replace the class type with "class", which causes the edito ...
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 ...
[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 ...
Chaos : Rigid body sleeps when very small external force is applied by AddForce
UE - Simulation - Core - May 25, 2022When a small external force is applied to the rigid body, the VSmooth value is reset in the ResetVSmoothFromForces function. Since this function ignores the current velocity, a very small velocity ...
[CrashReport] Assertion failed: !PinRef->bWasTrashed | UEdGraphPin::SerializePin()
UE - Gameplay - Blueprint - Aug 29, 2017This is a common and longstanding crash that has occurred since at least 4.15 and affected nearly 500 users. The CrashGroup was previously linked to [Link Removed], but that had specific repro step ...