Crash when rendering cinematic in a Separate Process without "-NoLoadingScreen" cmd argument

UE - Anim - Sequencer - Jul 5, 2016

Crash when rendering cinematic in a Separate Process without "-NoLoadingScreen" cmd argument. Occurs in 4.12 and 4.13 in both Matinee and Sequencer Error message: Assertion failed: SizeX > 0 && S ...

Foliage lightmaps for LODs does not look correct

UE - World Creation - Worldbuilding Tools - Foliage - Jun 21, 2016

When using the foliage tool with any mesh that has a LOD the lightmap generates artifacts for the instance. The base LOD will have correct looking lightmaps, however when pulling back and seeing the ...

Crash When Attempting to Add Existing Streaming Levels Already Present in the Levels Window

Tools - Aug 10, 2017

This Jira was created from CrashReports submitted by the public due to the high number of occurrences. Descriptions from users are provided below. Error message: Access violation - code c0000005 ( ...

Some Planar Reflections not working on more than one surface if it's a single mesh

UE - Graphics Features - Nov 2, 2016

Planar Reflections only work with a single surface or limited surfaces when it's a single mesh vs multiple meshes making up the piece. Attached is a sample project that will show the issue. Level ...

Crash when resizing window using Quad Stereo Buffer

UE - Virtual Production - nDisplay - Oct 2, 2019

We noticed crashes in our application when we attempted to resize a window or switch to full-screen mode. Hence, resizing windows and switching to full screen will result in a crash on Unreal Engine ...

Internal Compile error received from rearranging Format Text nodes

UE - Gameplay - Blueprint - Dec 18, 2014

Internal Compile error received from rearranging Format Text nodes Output Log of Error: LogBlueprint:Error: [compiler] Error Internal compiler error inside CreateExecutionSchedule (site 2); please ...

Crash Importing Skeletal Mesh LODs with a lot of morph targets

OLD - Anim - May 18, 2016

Crash Importing Skeletal Mesh LODs with a lot of morph targets Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 785] Array index out of bounds: 2 from an ar ...

When using Perforce, saving a level over another leaves the target umap file as "marked for delete"

UE - Editor - Workflow Systems - Mar 11, 2025

When working on a level asset and using command "File – Save Current Level As..." to save it over a different level asset, the engine first deletes the target level (that's going to be overwritten) ...

5.5 Static Mesh Import Pipeline Regression

UE - Editor - Content Pipeline - Import and Export - Apr 25, 2025

This question was created in reference to: [Link Removed] This post references the first post because this problem was not discovered till now. I think it was masked because the issue appears to be ...

Controller input changes for network players based on which window has focus

UE - Gameplay - Input - May 23, 2016

When testing networked multiplayer with two controllers, if the server window (editor) has focus, controller 1 controls the server character and controller 2 controls the client character. If the c ...