Logic error in TRange::Difference causes crash when you Trim and Preserve Left/Right and unbounded Attach section in the sequencer

UE - Anim - Sequencer - Aug 1, 2024

TRange::Difference function does not handle bounds correctly, causes crash in the sequencer when "Trim And Preserve Left/Right" is used in the user's example project. User provided a potential fix: ...

bIncludeComponentLocationIntoBounds breaks bounds calculations

UE - Anim - Runtime - Aug 13, 2025

Bounds generation when bIncludeComponentLocationIntoBounds is active is broken. Both the calculation of the local bounds and the world bounds are incorrect (see screenshot). When that flag is acti ...

Physics Mover: AI movement and collisions can cause sharp increase in velocity

UE - Gameplay - Player Movement - Mover - Aug 19, 2025

A pawn using the physics mover and using AI movement can sometimes gain an ton of velocity quickly upon colliding with another physics object. It seems to fix it self and revert back to it's origina ...

Crash on stopping PIE after using DemoRec in PIE

UE - Networking - Jan 20, 2016

Crash on stopping PIE after using DemoRec in PIE. Possibly related to [Link Removed] which must be fixed, but happens upon stopping PIE. Reproduced in 4.11.0 Preview 3 binary and Main (//UE4/Dev-Ma ...

Calling functions that have an implicit WorldContextObject parameter in a Blueprint function library will give a compile error about a missing __WorldContext pin

UE - Gameplay - Blueprint - May 21, 2015

Calling functions that have an implicit WorldContextObject parameter (line trace, execute console command, etc) in a Blueprint function library will give a compile error about a missing __WorldConte ...

Can't PIE or Save: Editor gets into odd state when editing parameters.

Tools - Jul 20, 2016

I've seen this happen in other areas of the editor as well: Data Table fields (floats) for example. Manually typing in numbers to fields seems less prone to this error; using spinners to drag value ...

iOS movie become laggy and crashes when played in iPhone 6/6s.

UE - Platform - Mobile - Feb 24, 2017

Movie play in iOS is laggy and crashes in some movie. This issue seems to be happening when the movie is played in umg widget. Tested in 4.14.3 4.15 Dev_Mobile Latest as of 2/24 Original UDN post ...

DataAssets with a field called "Name" can cause multiple Name columns to appear in the content browser

UE - Editor - Content Pipeline - Content Browser - Jul 18, 2017

A DataAsset with a FText property called "Name" will confuse the content browser, causing it to create a new column each time the folder containing the DataAsset is entered. This appears to be a cor ...

Prompt for camera permissions when running Google VR plugin

UE - Platform - XR - Mar 7, 2018

Need to update these UDN threads when the issue is fixed. https://udn.unrealengine.com/questions/401360/ios-shipping-build-crash.html https://udn.unrealengine.com/questions/428225/about-ios-ship-b ...

Tiled Landscape LOD doesn't work with World Origin Rebasing

UE - LD & Modeling - Terrain - Landscape - Apr 26, 2018

Using the Landscape LOD system with World Origin Rebasing causes the LODs on the landscape to mess up. This only appears with imported tiled landscape where the main actor is in the persistent level ...