Unreal Engine Issues
Unreal Engine Issues
Copying collapsed graph with a node with a custom Exec pin results in duplicate pin name
UE - Framework - Blueprint Editor - Aug 17, 2022When duplicating a collapsed blueprint graph which has a node with a custom Exec pin, this results in blueprint compilation error that a duplicate named pin is found. Duplicated exec pins aren't ass ...
FAnimUpdateRateParameters::GetInterpolationAlpha appears to be returning an invalid value for TrailMode
UE - Anim - Aug 5, 2023It appears that FAnimUpdateRateParameters::GetInterpolationAlpha is not returning a sensible value when running in TrailMode. Currently the only variable in the calculation is EvaluationRate which ...
BlackmagicMediaSource causes a memory leak if "Just-In-Time Rendering" option is ON.
UE - Virtual Production - Oct 31, 2023Since 5.3, BlackmagicMediaSource causes a memory leak. This didn't happen on 5.2. You can see the leak on PIE. [Image Removed] [Image Removed] If "Just-In-Time Rendering" option in the MediaB ...
FInstancedStruct member uproperties are not cached when "Generate Optimized Blueprint Component Data" is enabled
UE - Framework - Blueprint - Nov 18, 2025A licensee has encountered an issue where their FInstancedStruct isn't being gathered into CachedPropertyData when "Generate Optimized Blueprint Component Data" is enabled. The changes in [Link Remo ...
Instanced Actors: Moving element in editor is not undoable
UE - Engine Scaling - Mass - May 30, 2026Context Instanced Actors can be moved by unchecking Lock Instance Locations on an IAM, and double-clicking into the actor → comp → instance to select an instance. Problem Moving an IA via the giz ...
Blueprint Editor: BP functions display dropdown instead of checkboxes for uint8 enum parameters
UE - Gameplay - Blueprint Editor - Aug 8, 2017I traced through the callstack and it looks like the problem is as follows:in order for the BP function to compile, its enum parameter must be uint8, because that is the only type supported by BP fu ...
Crash when creating new projects or converting copies of old ones in Japanese
UE - Editor - UI Systems - Slate - Dec 4, 2014There's a crash in FCharacterList::GetKerning() when using the editor in Japanese that is apparently fixed in one of these three changelists: CL# 2370014, 2370050, and 2370040 But they were not ...
Blueprint 'Select' node: nodes connect to all input pins are evaluated while only one input is needed
UE - Gameplay - Blueprint - Aug 15, 2015Originally marked Won't Fix in 2017. Issue reopened on May 1, 2024. All inputs of a Select blueprint node are evaluated, even though in the end only one value is selected. This is wasteful work. ...
Package build fails after disabling VR plugins
UE - Platform - XR - Mar 27, 2017Package build fails after disabling VR plugins and launching the project The error message that pops up is: Fatal error: [Link Removed] [Line: 353] Missing global shader FPixelShaderDeclaration, P ...
Output Pins Not deleting on DoOnce MultiInput
UE - Gameplay - Blueprint - Apr 13, 2017When using the DoOnce MultiInput node in blueprints, deleting a newly added pin on the input side will not delete its corresponding output pin. Adding a new pin after that will create the result lik ...