Unreal Engine Issues
Unreal Engine Issues
Crash on Mac on exit.
Media Framework - Aug 17, 2020A licensee reported trouble with a crash on exit on Mac. They discovered that the file AvfMediaPlayer.cpp, on the function Open there is this piece of code:// Force the AV player to not be able to ...
Regression - Nav mesh is not generated on BSP brushes after loading a map
UE - AI - Navigation - Dec 18, 2024In UE 5.5, when loading a map and selecting "Build – Build Paths", the nav mesh is not generated on any BSP brushes (although it is correctly generated in static meshes). This did not happen in earl ...
Regression - Nav mesh is not generated on BSP brushes after loading a map
UE - AI - Navigation - Jan 14, 2025In UE 5.5, when loading a map and selecting "Build – Build Paths", the nav mesh is not generated on any BSP brushes (although it is correctly generated in static meshes). This did not happen in earl ...
FAnimationRuntime::BlendPosesPerBoneFilter() causes an assertive crash when Skeletal Mesh LOD is changed
UE - Anim - Runtime - Nov 1, 2023The crash occurs from "check(BoneBlendWeights.Num() == NumBones);" This crash occurs when the following conditions are met;The skeletal mesh LOD is changed.The number of bones is difference between ...
Content is Missing from Cook and indeterminism: StaticMeshComponents in Blueprints that copy data into themselves from StaticMesh have indeterminism due to StaticMesh not yet finished loading, postloading, or building
UE - Foundation - Nov 12, 2025Content is Missing from Cook warnings are warnings reported at the end of cook phase of a project's data build. They report that data used by a cooked package will not be available at runtime. This ...
Undo after disconnecting a target pin will cause a series of internal compile errors
UE - Gameplay - Blueprint - Mar 15, 2016Undo after disconnecting a target pin will cause a series of internal compile errors User Description: I've run into what I think is a bug when attempting to compile a blueprint after mistakenly b ...
[AI] Bad entries in NavigationRepository for Box collision with bCanEverAffectNavigation set to false
UE - AI - Navigation - Oct 26, 2025Some components continue to dirty the navigation state even if bCanEverAffectNavigation is unchecked. Behavior appears very similar to an existing bug, [Link Removed] ([Link Removed]), which invol ...
UE4Editor_SlateCore!TSharedFromThis<SWidget,0>::AsShared() sharedpointer.h:1221
Tools - Apr 18, 2017This bug report was entered as new crash groups appeared linking to [Link Removed] which was marked as fixed for 4.15.1 and the previous reproduction did not reproduce the issue Error message: Ass ...
Float Curve evaluation may yield completely wrong results due to floating-point precision issue
UE - Anim - Runtime - Oct 31, 2024Note: This is possibly related to [Link Removed]. For some inputs, function UE::Curves::WeightedEvalForTwoKeys() inside file "CurveEvaluation.cpp" can incorrectly return the value of the first key, ...
Reference to control rig can be lost on actors with multiple skeletal mesh components
UE - Anim - Rigging - Control Rig - Apr 4, 2023In the attached project, when we initially add a control rig track for the actor with multiple skeletal mesh components, we add the control rig for the correct component because FControlRigParameter ...