Unreal Engine Issues
Unreal Engine Issues
Alt-tabbing out of a Standalone App or packaged version of a game does not trigger LostFocus or ReceiveFocus
Tools - Sep 9, 2015If a user uses Alt-tab to change to another window, the ReceivedFocus and LostFocus functions are not called as they would usually be called when using something such as Shift+F1 or Ctrl+Esc. Note: ...
FIXIF: Using the Merge Blueprints feature crashes the editor
UE - Gameplay - Blueprint - Feb 18, 2015Using the Merge Blueprints feature crashes the editor. This repro is for clicking between the error and warnings while merging, but the editor will generally crash if the Merge is finished or if an ...
[CrashReport] Mac crash - libobjc.A.dylib!objc_retain() [UnknownFile]
UE - Platform - Apple - Nov 10, 2017This is a longstanding but low frequency Mac crash. User DescriptionsChanging camera shake values and testing in a new editor window Callstack from Log[2017.11.09-19.23.22:392][ 63]LogMaterial: Mi ...
Blueprints not marked dirty when variables in referenced actors are renamed
UE - Gameplay - Blueprint Compiler - Feb 20, 2018Blueprints using renamed variable do not indicate that they need to be recompiled. (However errors are shown on play) It is possible to not see an error if you add a variable with the same name as ...
Niagara Scalability Crash When Processing Significance
UE - Niagara - Jun 4, 2025Method FNiagaraScalabilityManager::ProcessSignificance() iterates on indices from Context.SignificanceIndices and uses them to access the State and ManagedComponents arrays. It can then decide to cr ...
Editor crashes when changing skeletal mesh if another skeletal mesh component is attached when using master pose node
OLD - Anim - Jan 27, 2020The crash only occurs if the additional skeletal mesh component is used with Set Master Pose Component (see ToggleAttach function in the TopDownCharacter BP). It doesn't seem to matter what mesh we' ...
Set user focus for player 0 will cause other local players to lose input
UE - Gameplay - Input - Feb 28, 2019When the player at index 0 sets its user focus it will cause other players to lose input. This does not occur when setting the user focus of players with an index higher than 0. ...
World Source in Take Recorder does not record auto-tracked actors properly
UE - Virtual Production - Tools - Take Recorder - May 23, 2025The Take Recorder plugin allows for multiple sources to be recorded during gameplay. The World Source is expected to record everything in the level when the Autotrack Actors option is enabled. Once ...
Crash after adding Virtual Bone, then Creating Asset
OLD - Anim - Jul 5, 2017Occurs on? 4.16 - 3466753 - YES 4.17 - 3521650 - YES Error message: Assertion failed: RefBonePose.Num() == NumBones [Link Removed] [Line: 4400] Source Context:4387 ResetAnimation(); 4388 ...
Exception generated launching Horde Agent built with 5.6
UE - Foundation - Horde - Server - Jul 28, 2025The source of the problem seems to be using IOptionsSnapshot with a Singleton. Per the MS documentation for IOptionsSnapshot, "Is registered as Scoped and therefore can't be injected into a Singleto ...