Removing a parameter from a blueprint function in a library can cause actor classes calling it to lose their parent or instance data

UE - Gameplay - Blueprint - Oct 4, 2018

Compile errors caused by an actor calling a function with something hooked up to a removed parameter can cause that actor to lose it's place in the hierarchy. Typically, the actor will be fixed once ...

Unexpected Changes in Saturation/Contrast of Colors when upgrading project to 4.15

UE - Graphics Features - Jan 30, 2017

When upgrading a project to 4.15 (in my case from 4.14.3), the colors seem to have shifted in contrast/saturation. It is not a huge difference, but noticeable enough to affect the overall result of ...

Controller::GetPawn() returns NULL in 4.9

UE - Gameplay - Sep 3, 2015

Making a call to GetPawn in an AIController class will return NULL which will crash when that return value is used. This is a regression as the call is made successfully in 4.8.3. Working CL: Work ...

Instance UObjects in an array on an Actor replaced by pointers to other objects in array while PIE

UE - Gameplay - Blueprint Runtime - Sep 20, 2018

When this issue occurs printing out the addresses of each item in the array shows that elements 2 and 3 have the same address, so for some reason the second element's value is being overridden by th ...

SunTemple scene does not update properly on iPhone 6S

UE - Platform - Mobile - Jul 18, 2017

On the 6S, the SunTemple scene is almost unresponsive. As the player uses the thumbsticks, the lightmaps from the windows rotate to mach the player's movement; but they are the only thing. This doe ...

Print String node will stop printing to the screen if PIE is exited while Gameplay Debugger is active

UE - Gameplay - Feb 15, 2017

Print String node will stop printing to the screen if PIE is exited while Gameplay Debugger is active. Restarting the editor fixes the issue. ...

UV merging issue when merging meshes with multiple materials

UE - LD & Modeling - Modeling Tools - Mesh Editing - Jul 15, 2019

See https://udn.unrealengine.com/questions/505632/view.html for more details Repro: -Have a mesh with 3 sections and 3 materials, assign section 1 to material 1 and section 2&3 to material 3. -Pla ...

[CrashReport] - TRawMessageHandler<FTargetDeviceServicePong,FTargetDeviceProxyManager>::HandleMessage()

UE - Platform - Mobile - Jan 25, 2018

User comments:Packaging Android Crash with similar callstack fixed in 4.16: [Link Removed] I verified that the repro steps in that bug do not cause a crash in 4.18.3 Similar crash on Mac: [Link Re ...

Enum Compare Condition causes crash when resetting default value of right field in State Tree's Enter Conditions

UE - AI - StateTree - Feb 11, 2026

In FStateTreeCompareEnumCondition::GetDescription, the Left.Enum value is mistakingly used when setting the RightValue. This causes crashes when resetting the default value of the Right field in an ...

Widget With Spinbox Crashes When Destrcutor Is Called With Multithreaded Destruction Enabled

UE - Foundation - Core - UObject - Feb 28, 2020

When a widget with a spinbox is calls it's Destructor with "Multithreaded Destruction" enabled the engine crashes. I have tested in 4.23.1, 4.24.3, and 4.26 Main with "Multithreaded Destruction" dis ...