Unreal Engine Issues
Unreal Engine Issues
"Enable Stencil Test" Mobile crash
UE - Graphics Features - Sep 10, 2019A material with 'enable stencil test' will crash on mobile. Enable Stencil Test is a new option in materials as of 4.23 Confirmed with OpenGL 3.1 + 2 and Vulkan on Pixel XL Also Crashes on iOS ...
Scene Color node with UV input on a transparent material renders incorrectly in stereo
UE - Platform - XR - Jan 19, 2021From Licensee: When we have Instanced Stereo enabled, all our materials that use Scene expression nodes (SceneDepth, SceneColor, etc...), render incorrectly in the right eye. It only happens to the ...
Deadlock in UAnimationSequencerDataModel::Evaluate where FScopeLock Lock(&EvaluationLock) blocks execution indefinitely
UE - Anim - Nov 4, 2025When both the Sequencer Editor and an Animation Curve Editor are open for the same animation asset, the editor freezes completely upon editing the curve. Analysis indicates that the freeze is caus ...
Possible incorrect pointer manipulation in BeginPackageCacheForCookedPlatformData
UE - Foundation - Core - Cooker - Dec 12, 2017In UCookOnTheFlyServer::BeginPackageCacheForCookedPlatformData(), there is a pointer to int32 called CurrentAsyncCache that is used as an index. It's value is dereferenced before it is checked, but ...
"Save Current As" is not fully loading the newly-saved level
Tools - Mar 15, 2017Workaround: 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, 2015Exporting 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, 2025Issue 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, 2016Error 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, 2024CriticalErrors 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, 2019When 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 ...