Cook non-determinism when serializing UObject pointers pointing to garbage

UE - CoreTech - UObject - Aug 25, 2025

There's a cook determinism issue in the way UObject unversioned serialization handles UObject pointers pointing to garbage. Depending on GC timing, it can either be skipped (as a property matching C ...

Steam friends list is duplicated when opened for a second time in the packaged version of Shooter Game

UE - Networking - Jun 29, 2015

If a user is logged into a Steam account with between 1 and ~10 friends (Max depends on resolution, as it'll push the excess off the screen) and they open the friends list multiple times, it'll dupl ...

Sequences in sub-levels only fire events in the persistent level

UE - Anim - Sequencer - Mar 28, 2016

Sequences in sub-levels only fire events in the persistent level. I don't know if they're expected to be firing in all levels or just the sub-level ...

Compilation manager inhibit construction script to get other actor reference on the level when running construction script right after actor compile.

UE - Gameplay - Blueprint - Aug 9, 2017

Construction script execution following blueprint compile gets invalid actor reference if Blueprint compilation manager is enabled. For example, in the attached project, Right after blueprint compi ...

Event not saved correctly when duplicating Level Sequence

UE - Anim - Sequencer - Nov 21, 2019

This issue is similar to [Link Removed]. But I tested the shelve 10164190 mentioned in the comments. It didn't work. ...

Swapping the Child Actor Class of a ChildActorComponent back to a previously selected BP leads to an Editor crash from illegal Renaming

UE - Framework - Components - Sep 11, 2024

A fatal error occurs if we change a Child Actor Class from one BP (ex. "BP_A") to a different BP ( ex. "BP_B") and later change it back to the first BP (ex. "BP_A") without compiling the BP between ...

naming box collision in player character renames overlap begin event in actor calling player character

UE - Gameplay - Blueprint - Jan 28, 2016

naming box collision in player character renames overlap begin event in actor calling player character ...

FPS drop when deploying to a Mobile device

UE - Platform - Mobile - Feb 27, 2015

The FPS drop off of this users project is significant between version of UE4. I tested this issue on a Samsung Galaxy Note 10.1 2014 edition. I also tested on a iPad air 2 on 8.1. There was a sig ...

'Is Case Sensitive' option on the Switch on String node doesn't toggle correctly

UE - Gameplay - Apr 22, 2015

'Is Case Sensitive' option on the Switch on String node doesn't toggle correctly. User Description: The "Is Case Sensitive" option when you use a switch on string function in blueprint doesn't wor ...

FVoiceSerializeHelper doesn't add references to AudioComponent instances

UE - Networking - Apr 28, 2015

"FVoiceSerializeHelper doesn't add references to AudioComponent instances" ShooterGame crashes when following the repro steps provided by the licensee, listed below and on the UDN post. Crash image ...