Replacing a UI widget element and then undoing it causes the Widget Blueprint's UI elements to be deleted on editor restart

UE - Editor - UI Systems - Jan 25, 2021

When using the Replace With option and then undoing it, upon engine restart the Widget Blueprint's UI components are all removed from the Widget Blueprint. It seems the undo is crucial to the issue, ...

Compile on load crashes for classes within an abstract class

UE - Gameplay - Blueprint Compiler - Feb 20, 2021

When compiling on load in -game, a blueprint class that inherits from a native class that is marked within and the class that it is within is abstract, a crash will occur when FBlueprintCompilationM ...

The space between multi line text is gone in game when the text box is placed in a retainer box

UE - Editor - UI Systems - May 4, 2021

When using a Text Box with multiple lines inside a Retainer, the lines overlap with each other depending on the letters. It doesn't look this way in the Widget Designer. Additionally, it doesn't loo ...

Incorrect volume bounds check in FTranslucentLightInjectionCollector::AddLightForInjection

UE - Graphics Features - Apr 8, 2025

The 'VolumeBounds' array in FTranslucentLightInjectionCollector::AddLightForInjection is accessed as a pointer instead of with 'VolumeCascadeIndex' and thus fails bounds checks for the outer volume. ...

Certain combined Linear/Angular movements cause Client to freeze for several seconds

UE - Simulation - Physics - May 24, 2019

When using Replicated Movement, certain combined linear/angular movements cause the client to freeze for several seconds and then catch up to the server. This is a regression from 4.21.2 (CL-4753647 ...

RemoveAxisMapping() removes axis mappings of the same key regardless of Scale value

UE - Gameplay - Jun 26, 2019

When you remove an axis mapping using a specific key it will remove all mappings even if they have separate scales. The user found a fix that I verified that worked. In "InputSettings.cpp", which i ...

Imported TTF fonts rendering unknown glyphs for common characters

Tools - Oct 28, 2019

Imported TTF fonts rendering unknown glyph for previously-working characters such as ' or ! or , or ?. In 4.21 the font was working as expected. User states that custom fonts should be forward-compa ...

"NO ASYNC TICK" in Cascade viewport when adding a Skel Vert/Surf Location

UE - Niagara - Nov 7, 2019

Adding a Skel Vert/Surf Location node to a Particle Effect causes it to stop displaying particles and throws the warning "No Async Tick". Toggling Skel Vert/Surf Location off allows the Particle to ...

Crash to desktop after creating Level Sequence with Widget Blueprint

Tools - Nov 30, 2019

Newly created Level Sequence assets cant be opened when they have been created via Editor Blueprint Widget. They are created successfully through a button click for instance, but when you try to ope ...

Assertion failed: InputOboeStream != nullptr when changing levels with Android voice enabled

UE - Audio - Jan 7, 2020

Assertion failed: InputOboeStream != nullptr when changing levels with Android voice enabled User was able to workaround the issue by replacing Audio::FAudioCaptureAndroidStream::CloseStream() wi ...