Unreal Engine Issues
Unreal Engine Issues
Niagara Ribbon Facing Mode Custom Side Vector does not work correctly
UE - Niagara - Feb 28, 2020The Custom Side Vector facing mode is no different than the Custom facing mode on Niagara ribbons. The linked UDN has more information on a potential cause, as well as a proposed fix. It looks like ...
Normals are wrong on grouped sprites, causing issues when they are using lit materials
UE - Gameplay - Paper2D - Jul 12, 2016The normals for each sprite in a grouped sprite component are always as if the sprites were rotated (0,0,0), which is incorrect. Each sprite should have correct normals and look the same as if it w ...
WorldPartitionConvertCommandlet hits an assert when converting a persistent level that contains a sub-level with a landscape
UE - World Creation - Worldbuilding Tools - Nov 7, 2025Context: The Window tab allows a user to open the Levels window in order to add a sub-level to a persistent level. For Unreal Engine 5.0 and beyond, World Partition has made the Levels window obsole ...
New C++ Class (actor) fails to build
UE - Foundation - Cpp Tools - Mar 8, 2022While trying to create a C++ actor to test if it can be created with a custom Copyright notice specified in Project Settings, the Live Coding window returns a "Build failed" and error of: "ERROR: U ...
SkyLight makes level entire green on Android devices
UE - Platform - Mobile - Aug 10, 2016https://udn.unrealengine.com/questions/305453/skylight-makes-our-level-entire-green.html Licensee was seeing this only on this device: SM-G906S Android 5.0.1 Adding glFlush call in CaptureSceneToS ...
Multiple templates have Can't Find File warnings when cooking content for Mac
UE - Foundation - Core - Cooker - Jan 13, 2016The following Can't Find File warnings appear for the Flying Code and BP projects when cooking content for Mac.MainFrameActions: Cooking (Mac): UE4Editor: [2016.01.13-20.14.37:469][ 0]LogInit:Displ ...
Sphere Mask ArgInvHardness missing multiplication
UE - Rendering - Architecture - Materials - Jun 27, 2025Hi Epic, In MaterialExpressions.cpp UMaterialExpressionSphereMask::Compile(), hardness is not calculated the same way in both <if> conditions. One is missing a multiplication by 0.01f. Specificall ...
In -game in Editor, if streaming-in a LevelInstance and initialize its world partition, then leaving that cell and make it go outside the streaming grid, to re-enter it again, will trigger a check(!StreamingPolicy) if no GC has happened during that time.
UE - World Creation - Worldbuilding Tools - World Partition - Jan 27, 2025This crash can be fixed by adding a couple of || IsRunningGame() like it is done here: FGenerateStreamingContext Context = FGenerateStreamingContext() .SetLevelPackagesToGenerate((bIsPIE ...
Replacing blueprint assets causes editor to crash
UE - Gameplay - Blueprint - Jun 1, 2015When attempting to replace references of one blueprint with another a number of error message windows pop up ([Link Removed]) and the editor will crash. This is a regression since it was working in ...
Editor crash when Use Dynamic Material Instance is set to "True" on landscape
UE - LD & Modeling - Terrain - Landscape - Mar 23, 2018Setting "Use Dynamic Material Instance" to true in the landscape details will cause the editor to crash. Reproduced in 4.19.0 CL 3944462 and 4.20 Main. This feature is not available in 4.18.3. ...