Crash after network disconnection/pulling network cable

UE - Networking - Jul 11, 2019

A very unfortunate bug shipped in 4.22 that causes a crash in many cases when a client is disconnected from the network, such as when unplugging the network cable. This will be a cert failure on con ...

Landscape Layer Blend generates bad code for preview shader

UE - LD & Modeling - Terrain - Landscape - Sep 23, 2019

It breaks only when compiling the preview shader. Adding a preview weight to the Layer0 on the Layer Blend node fixes the problem. The source of the bug is in UMaterialExpressionLandscapeLayerBlend ...

Cash when entering Path Tracing view mode if r.Decal.NormalReprojectionEnabled true

UE - Graphics Features - Path Tracer - May 16, 2025

Cash when entering Path Tracing view mode if r.Decal.NormalReprojectionEnabled true The licensee has reported: This crash happens because the DeferredShadingRenderer tries to extract the normal GBu ...

DataTable::LoadStructData allocating wrong size

UE - Foundation - Core - Oct 5, 2016

Pointed out by a licensee here: UDataTableを読みこんだ際のメモリ破壊について When reading the `UDataTable, in DataTable::LoadStructData()` the contents of the struct are interpreted[Image Removed], but the size of ...

(Undo Crash in BPs) [CrashReport] UE4Editor_Core!rml::internal::Block::findObjectSize()

UE - Gameplay - Blueprint - Jul 25, 2017

This is a trending crash in the 4.17 Preview. There was one occurrence of this callstack months ago in 4.15.1, but a number of recent ones in 4.17. User DescriptionsI was pressing cltr+z severl ti ...

UDN : Mutable Trying to Access Invalid UEdGraph Pointer

UE - Anim - Mutable - Mar 6, 2025

Hello, We've started seeing a crash within Mutable when it tries to access the source graph in PIE. This only seems to be a problem when running a dedicated server as a separate process. We integra ...

Normal are different after Merge Actor on scaled objects

OLD - Anim - Feb 8, 2018

Normal are different after Merge Actor on scaled objects. If the actors aren't scaled, the issue doesn't seem to occur. A licensee is trying to use the Merge Actor tool to optimize their entire pro ...

Crash upon taking a screenshot on Gear VR

UE - Platform - XR - Jul 13, 2017

Using the shot console command or the RequestScreenshot function to take a screenshot in Gear VR causes the app to crash. This was tested on Android-19, ETC-1 configuration, with both Developer Mode ...

Crash when travelling during ability activation when URL contains "#"

UE - Framework - Jul 18, 2025

This issue is related to [Link Removed], where the "?listen" option sent on the URL to clients could cause issues with RPCs being called locally during travel. The fix to remove the "?listen" option ...

HiResScreenshot has incorrect masking when screenshot resolution scale does not match the viewport.

UE - Rendering Architecture - RHI - Sep 6, 2021

After a bit of investigation, the way to fix this would be to modify MergeMaskIntoAlpha to pass in the actual resolution scale and the requested size, and only mask the overlapping pixels. Currently ...