Unreal Engine Issues
Unreal Engine Issues
[CrashReport] Crash on Mac during cook - UEditorEngine::UpdateAutoLoadProject()
UE - Platform - Apple - Jun 6, 2017This is a top crash on Mac. This crash has only occurred on the 4.16.1 release (there are no records of it in 4.16.0). Repro steps are currently unknown, but the crash occurs in Commandlet mode and ...
[CrashReport] UE4Editor_CoreUObject!FScriptArrayHelper::EmptyAndAddUninitializedValues() [unrealtype.h:2703]
UE - Gameplay - Blueprint Compiler - Aug 15, 2017This is a trending crash coming out of the 4.17.0 release. Based on user descriptions, this crash occurs on Play or Compile for affected users. User DescriptionsAgain crashing when I hit playIF I C ...
[CrashReport] Assertion on Mac: Could not create a libwebsocket - FNetworkFileServerHttp::Init()
UE - Platform - Mobile - Jun 22, 2017This is a common crash on Mac that occurs in the 4.16 release. This appears similar to [Link Removed], which was closed with the 4.13 release. Users have not provided descriptions. Many (but not a ...
[CrashReport] Mac crash - TArray<FDeferredMacEvent, FDefaultAllocator>::ResizeGrow
UE - Platform - Apple - Sep 14, 2017This is a somewhat common crash on Mac that has affected users since 4.16. Users have not provided any descriptions of their actions when the crash occurred. Callstack from Log [2017.09.08-05.17. ...
Get Mouse Position Blueprint node returns different values outside of viewport depending on whether it was called from Event Tick, or within an Actor function
UE - Gameplay - Nov 15, 2018There seems to be a discrepancy between the output of Get Mouse Position node depending on whether the node is inside an Actor function or called from Event Tick. If the node is present inside a fun ...
Wrong WPO motion vectors due to Periodic World Space node
UE - Rendering - Features - May 13, 2026We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...
Crash when casting to owner from AnimGraph
OLD - Anim - Sep 6, 2016Crash occurs when casting back to the pawn owner from the Anim Graph. In this case, it is being used for "Copy Pose from Mesh" Workaround: Cast to Owner from Event Graph, defining variable as the ...
[CrashReport] Crash on Mac related to editor close
UE - Platform - Apple - Jun 6, 2017This is a long-standing Mac crash that occurs with low frequency, but has affected more than 500 users since it started (possibly in the 4.11 release) It has recently been experienced internally by ...
Unexpected behavior when Actor Parenting in the World Outliner of a WP map
UE - Engine Scaling - Streaming - World Partition - Nov 23, 2021Licensee reports the following in the UDN: There seems to be some other erratic behavior when using parenting in world outliner (i.e. drag and drop one actor on another one in world outliner).Since ...
Nanite: unused VertexInterpolator node disables Opacity Mask (material renders opaque)
UE - Rendering - Architecture - Jun 8, 2026On Nanite meshes, placing a VertexInterpolator node in a material graph without using it (unconnected, or routed through a disabled static switch) silently breaks the Opacity Mask and the material r ...