"Save Current As" is not fully loading the newly-saved level

Tools - Mar 15, 2017

Workaround: Navigate to and open the newly-created level in the Content Browser prior to LaunchOn. After using the Save Current As tool, Game runs into error when trying to LaunchOn. Editor display ...

Exporting Mannequin to Blender then Re-importing to UE4 Incorrectly Rotates Animations by 90 Degrees

OLD - Anim - Jun 16, 2015

Exporting the UE4 Mannequin to Blender then re-importing to UE4 breaks the animations, causing them to reimport rotated 90 degrees ...

Control Rig - Undo doesn't function correctly with proxy and multi bone controls

UE - Anim - Rigging - Control Rig - Oct 26, 2025

Issue from my Technical Animator where the undo operation in Control Rig doesn't work as expected on Proxy Controls. He has recreated the issue using the "Control Rig Samples Pack" and recorded a vi ...

[CrashReport] UE4Editor_Slate!FMenuStack::DismissInternal() [menustack.cpp:582]

UE - Editor - UI Systems - Slate - Apr 15, 2016

Error Message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 785] Array index out of bounds: 1 from an array of size 0 Source Context: 567 } 568 } 569 ...

Crash handling: Prevent reports of assertions during shutdown after an assertion

UE - CoreTech - Aug 8, 2024

CriticalErrors in FWindowsErrorOutputDevice::Serialize (and other platforms) run some code after the error is detected rather than immediately terminating the process. Some of this other code is spe ...

Engine Crashes When Trying to Add an Entry to a TMap in a Nested Struct That is an Element of an Array

Tools - Oct 3, 2019

When trying to add an entry to a TMap in a nested struct that is an element of an array the engine crashes. This doesn't happen if it is not an array of the nested struct. Attached are .h and .cpp ...

[CrashReport] UE4Editor_MaterialEditor!SMaterialLayersFunctionsInstanceTree::UpdateThumbnailMaterial() [smateriallayersfunctionstree.cpp:1128]

Tools - Feb 27, 2018

No user comments in crash group 1114 for (TSharedPtr<FStackSortedData> Group : AssetChild->Children) 1115 { 1116 if (Group->ParameterInfo.Association == InAssociation) ...

Inconsistent ListView entry sizes can prevent the ListView from being scrolled to the bottom

UE - Editor - UI Systems - Slate - May 4, 2022

Since the contents of a ListView are virtualized, the ListView estimates the size of the scroll box's contents based on the on-screen elements. This can lead to some situations where DistanceFromBot ...

Groom Hair Visual Issue with RBF Interpolation Enabled

UE - Graphics Features - Feb 19, 2025

When "RBF Interpolation" is enabled in the Groom settings, applying an Animation Sequence to a Skeletal Mesh that animates at a position far from the world origin causes the bound Groom shape to bec ...

[CrashReport] UE4Editor_Persona!FBoneDescription::SetScore() [bonemappinghelper.h:31]

OLD - Anim - Sep 14, 2017

This is a somewhat common crash that appears to occur only in 4.17.1 (possible regression?). Users have not provided any description of their actions when the crash occurs. Source Context 20 ...