Crashes when attempting to use an Instanced Struct inside Control Rig / Rig VM

UE - CAPT - Control Rig - Mar 17, 2025

Currently, the Control Rig Editor allows the user to use the "Instanced Struct" type, for example for a variable or function input/output. However, this type does not seem to be properly supported ( ...

FCameraShakePreviewer retains world-outered UCameraShakeBase instances indefinitely, fataling CheckForWorldGCLeaks on editor map change

UE - ACT Character - Sequencer - Aug 21, 2026

FCameraShakePreviewer is an FGCObject that strongly references the UCameraShakeBase instances it previews, and creates them outered to the previewed UWorld. Nothing releases them on world teardown, ...

Shadow flicker with dynamic lighting at low cascade levels when FOV changes

UE - Graphics Features - Sep 1, 2017

When using low shadow settings there is a flicker that occurs when changing a camera FOV, the flicker will end as soon as the FOV has finished adjusting to the new FOV. This can occur when:Using a ...

Clients Joining a session destroy and recreate all actors in the level upon joining

UE - Networking - Apr 28, 2015

When a new client joins a server all of the actors will be replaced with new copies of themselves. This will cause things like the construction script and event begin play nodes to fire off every ti ...

Consistent Crash using Cinematic Viewport on Linux

UE - ACT Character - Sequencer - Aug 13, 2026

We are getting multiple crashes on 5.8.1 when trying to use the cinematic viewport on Linux, the most consistent way it's been reproduced is by clicking on the blue frame number to the left of the c ...

ServerTravel command doesn't work in PIE using seamless travel

UE - Gameplay - Aug 19, 2015

The "servertravel" command doesn't function when running ShooterGame in Editor. A warning will show up in the Output Log: LogWorld:Warning: UWorld::ServerTravel: Seamless travel currently NOT supp ...

Setting multiple identical actors to replicate movement will crash on PIE with multiple players

UE - Networking - Jan 28, 2015

If ten or more of the same actor in a level have the "replicate movement" checkbox set to true, the editor will crash on PIE if the number of players is set to 2 (or with 1/2/3 players if dedicated ...

Montage keyframes calculation error

OLD - Anim - Apr 28, 2016

Animations are not showing proper length when converted to Montage. Up to 98 frames (AFAIK) when converted to Montage, the Montage will show the correct number of keys. However, a 100-frame anima ...

UE4Editor modules file is not written to properly when packaging a plugin

UE - Foundation - Cpp Tools - Plugin System - Apr 8, 2019

The modules file that is generated when packaging a plugin appends a number to the end of the .dll reference, similar to hot reload modules. This causes the reference to refer to a nonexistent file. ...

Editor reports crashes and terminates for exceptions that would otherwise be cleared by structured exception handlers

UE - Foundation - Core - CrashReportClient - Jun 8, 2020

In 4.25.1, I added a vectored exception handler to capture unhandled exceptions to the Editor process. This handler runs too soon. It doesn't let the structured exception handlers run first where ma ...