Unreal Engine Issues

Tabbing out of exclusive fullscreen leaves the window & backbuffer in an incorrect state

With windows 10 there has come some new swap chains, which unfortunately messes some things with regards to fullscreen up. We've fixed a bunch in the renderer (which would downright cause crashes), ...

Editor Crash when trying to get Color data from Vertex buffer

When attempting to get the vertex color of an instance of of a static mesh that is painted after placing it in the World Viewport. The Editor crashes returning an "Unhandled Exception". The cause o ...

Preview Rendering Levels Do Not Display Supported Optimization Viewmodes in Viewport Dropdown

When attempting to set an optimization viewmode while using a Preview Rendering Level other than Shader Model 5, the Optimization Viewmodes dropdown is missing all of its options and instead display ...

FString.Mid doesn't react appropriately when given negative values for the Count variable

If you use a 5 character string (hello) to call the Mid function and provide 0 for start, -1 for count, it'll give you the entire string. This should either return an assert or treat all negatives a ...

Crash when adding Actor Array Element to a Sequencer Event Struct

Crash when adding Actor Array Element to a Sequencer Event Struct Error message: Assertion failed: 0 [Link Removed] [Line: 56] Source Context: 42 N = FName(*StringName); 43 ...

Crash when changing r.MaterialQualityLevel when FastGeo plugin enabled in cooked build

The engine crashes when the r.MaterialQualityLevel is changed in a cooked game that uses the FastGeo Streaming Plugin. The crash doesn't repro with the same steps in Editor, just in a cooked build. ...

LevelEditor: "Replace Actor" marks level as dirty even when using external actors

When using external actors, adding/removing/replacing/editing an actor instance inside a level does not cause any modification to the Level package, which helps reduce contention for the map file on ...

[CrashReport] UE4Editor_Slate!TAttribute<FText>::Get() [attribute.h:130]

This is a common crash affecting users in 4.16 User DescriptionsI imported an FBX and the editor crashed.alembic import from brekelwhats wrong with the ue4 alembic importer? Source Context 120 ...

Dragging and dropping new materials into Dynamic Material Instance slot results in crash

[CrashReport] UE4Editor_SlateCore!FHittestGrid::GetBubblePath() [hittestgrid.cpp:145]

This is a trending crash coming out of the 4.18 release. Users have not provided any descriptions of their actions when the crash occurred. Based on the affected project names, this crash seems co ...