When importing static mesh using interchange and collision is generated, the asset does not have Collision Generated set to true

UE - Editor - Content Pipeline - Import and Export - May 19, 2025

Context: The Interchange Framework is Unreal Engine's import and export framework. When importing a mesh without collision, collision can be auto-generated. Problem: The problem is when importing s ...

Water tiles flicker in and out of visibility with instanced stereo enabled.

UE - Graphics Features - Jun 16, 2025

Water tiles flicker in and out of visibility when playing in VR with instanced stereo enabled. Requires instanced stereo rendering to be enabled (does not require forward shading to be enabled) Must ...

If PIE is paused using the 'Pause key', the Pause or Resume buttons on the toolbar will no longer start PIE

Tools - Feb 5, 2015

If PIE is paused using the 'Pause key', the Pause or Resume buttons on the toolbar will no longer start PIE. You have to make sure that the icon is toggled to Pause, select the viewport, and then p ...

[CrashReport] Assertion failed: OLEReferenceCount == 0 in UE4Editor_SlateRHIRenderer!FSlateRHIRenderer::DrawWindows_Private()

UE - Editor - UI Systems - Slate - Aug 22, 2017

This is a regular and longstanding crash in 4.17 that has occurred since at least 4.14. Users have not provided any descriptions of their actions when the crash occurred. There has been some previo ...

iOS Show External Login UI Blueprint Node fails on new iOS devices

UE - Online - Jun 6, 2019

I have been trying to test iOS online subsystem functionality for my game and thought that this blueprint node was just broken. This bug will probably catch many UE4 developers that are new to iOS b ...

Static Mesh imported from USD file has empty UV channel

UE - Editor - Content Pipeline - Import and Export - Oct 6, 2020

When importing static mesh from USD file then it has the wrong amount of UV channels. Selecting a UV channel shows an empty area in the viewport. Regression: YES - not reproduced in 4.25.3 produc ...

AllowCommandletRendering D3D12 device crash

UE - Graphics Features - May 10, 2021

Forward Rendering causes Volumetric Material to not render against background

UE - Graphics Features - Nov 15, 2022

Regression: Tested in UE5/Release-5.0, and the issue is reproduceable. This issue appears to occur when the SkySphere is deleted from the level, as leaving the SkySphere in the level causes the Vol ...

OnSmartLinkReached Event Not Firing in PIE

UE - AI - Sep 20, 2016

The OnSmartLinkReached event is not firing in PIE. This is a regression. In 4.12.5 the event fires as expected. Found in 4.13.0 CL 3106830 Reproduced in 4.14 Main CL 3129233. ...

Client crash on seamless travel in DataReplication with lag

UE - Networking - Jan 11, 2016

When server traveling, client may crash due to lag while attempting to replicate object/property. ...