Constant Crashes on OS X 10.10.1

UE - Platform - Apple - Dec 15, 2014

User (Omri) on Mac running OS X 10.10.1. on MacBook Pro (17-inch, Early 2009 Experiencing Crash. Cannot reproduce. Crash Reporter: N/A Callstack: MachineId:1E07B9CE2F4554A7C3F421A9DD97AFB5 EpicAc ...

Crash undoing variable change in Animation Blueprint.

OLD - Anim - Aug 1, 2016

Crash occurs when the user changes a variable in the animation blueprint, and then undo's the change. Note that this occurs with any variable being used, but the callstack will be some what differe ...

When using OpenLevel to transition to a level with WorldPartition enabled during PIE, the log outputs "Failed to load '/Game/MapName': Can't find file."

UE - World Creation - Worldbuilding Tools - May 31, 2022

Outputs warning logs when transitioning to the World Partition level with OpenLevel. This only occurs in PIE, not in Standalone or Package builds. In PIE, it appears that the package failed to load ...

Mobile Map loading times have increased from 4.12 to 4.13

UE - Platform - Mobile - Oct 4, 2016

The loading time from 4.12 to 4.13 on mobile devices seems to have increased quite a bit. My results: 4.12.5 Windows 7 - Launch On: Loading Level 2 - .51 Loading Level 3 - .74 Loading Level 1 - .73 ...

The process may not return to the root node after the Wait Task is completed.

UE - AI - BehaviorTree - Sep 14, 2021

If the Wait Task is completed for the first frame, it may not return to the root node even after Finish. This can be avoided by increasing the wait time of the Wait Task (see CaseOK.mp4). When this ...

Detour AI Controller Not Functioning Properly

UE - AI - Oct 30, 2015

Using AI Detour in 4.9.2 works as expected, however, when upgrading a project from 4.9.2 to a newer version, the AI pawns fail to properly navigate around each other when moving to their respective ...

Widget components and widgets in screen space are not the same color

UE - Editor - UI Systems - Jun 27, 2016

Widget components appear to be affected by lighting. This causes differences in color between widget components and widgets that have been added to the viewport. ...

Blendspace Animation Lag for Morph Targets

OLD - Anim - Sep 11, 2015

Blendspace animations of morph targets play at a slightly but noticably different rate between the 4.8 and 4.9 version of the UE4. ...

Passing array from blueprint to C++ causes performance drop

UE - Gameplay - Blueprint - Sep 8, 2015

Passing a blueprint array as an argument to a C++ function causes a spike in Frame rate, game and GPU. This spike is noticeable when using UnitGraph. Attached screenshots show difference in UnitGr ...

Blurry RVTs after camera jump

UE - Graphics Features - Aug 7, 2025

When using Runtime Virtual Textures (RVT) on landscape in UE 5.5+, nearby tiles may remain blurry (low-resolution mips) after launching PIE or making large camera jumps (e.g. via bookmarks or viewpo ...