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 ...

[Debug Tools][Crash] - Enabling au.editor.ForceAudioNonStreaming causes editor to crash the next time the user PIEs

UE - Audio - May 31, 2022

Encountered while going through some debug commands. Repro 3/3. Crash Reporter Link: [Link Removed]Assertion failed: ChunkIndex != 0 [File:E:\User\Engine\Source\Runtime\Engine\Private\AudioStreaming ...

Duplicated Blueprint Causes Incorrect Target for Events

UE - Gameplay - Blueprint - Oct 15, 2015

Duplicating a blueprint that has a node hooked up to BeginPlay causes the BeginPlay in the duplicate blueprint to target the original blueprint. This does not appear to affect functionality. Occur ...

Bound Variables In UMG Are Deleted As Unused If Not Used In The Graph Window

UE - Editor - UI Systems - Mar 18, 2020

If a variable is bound in the Design Window of a User Widget asset it will be deleted if you use the menu option "Delete all unused variables". Found in 4.24.3 CL#11590370 Reproduced in 4.23.1 CL#9 ...

Mutable compile hangs indefinitely when using Customizable Object Extension Data Constants

UE - Runtime - Mutable - Oct 25, 2025

I am getting a CO compile to hang indefinitely while compiling. It seems to be caused by the optimization in LocalLogicOptimiserAST that tries to convert 3+ conditionals into a switch statement. It ...

Meta Quest - Visual Artifacting in right eye with Lumen enabled and effects quality set to High

TM - VR - May 9, 2025

Reported in SF [Link Removed] On Meta Quest headsets, when Lumen is enabled for VR, setting the Effects Quality to High can cause visual artifacts to appear in reflections in the right eye of the h ...

World Partition Converter- Soft object pointers to actors kept in scripted sublevels are incorrectly remapped to the main world during in place conversion

UE - Engine Scaling - Streaming - World Partition - Jul 1, 2022

From user:"We have ran into an issue with soft object pointer fixup/remapping with the World Partition converter. If you have a sublevel that contains a level script and an actor that is hard refer ...

Trigger Volume Blocks First-Person Template Projectile

UE - Simulation - Physics - Nov 2, 2015

When playing in editor, if you fire your weapon at a trigger volume, the projectiles will bounce off of the volume, regardless of the fact that the collision is set to Query Only. This collision als ...

Procedural Sound Wave Fails to Play when returning 0 bytes in GeneratePCMData callback

UE - Audio - Aug 2, 2016

Returning 0 bytes in GeneratePCMData results in the procedural sound wave not continuing to play audio. Instead of returning 0, we need to return an empty buffer if the procedural sound wave doesn't ...

Ensure triggered inside Range Struct Customization when Property Node is no longer valid (e.g. when editing FFloatRange while FRuntimeFloatCurve editor is visible) [Ref. UE-341339]

UE - Editor - Verse Class Editor - Nov 12, 2025

[Link Removed] Closed was fixed by CL 46990575, successfully avoiding an ensure condition inside FIntervalStructCustomization::S ...