Unreal Engine Issues
Unreal Engine Issues
Datasmith - Lights imported with incorrect transforms
TM - Interoperability - May 6, 2025Reported in SF [Link Removed] In Twinmotion 2025.1.1, lights imported through Datasmith appear with incorrect transforms. Lights will appear rotated 90 degrees about the Y axis with an offset. Test ...
Enabling Preview Rendering Level Mobile GLES3.1 on Map With Vector Fields Results in Editor Crash
UE - Platform - Mobile - May 21, 2018Reproduced Crash on 4.18.3, 4.19.2, and Main CL 4081612. Licensee states: Based on a quick inspection of the code, it seems FVectorFieldVisualizationVertexFactory::ShouldCache() returns false (req ...
Network profiler can report sent RPCs despite a null ViewTarget preventing the send
UE - Networking - Nov 17, 2020Due to the hard-coded 1.5 second timeout for clients in UNetDriver:if ( OwningActor != NULL && Connection->State == USOCK_Open && ( Connection->Driver->GetElapsedTime() - Connection->LastReceiveTime ...
Niagara Data Interface "Errors and Warning" section on Module Details not updating when error messages change
UE - Niagara - Aug 14, 2025This is a regression: it worked correctly up to UE 5.5, but not in 5.6 or mainline latest. Possibly caused by CL 40093049. Class UNiagaraDataInterface provides virtual method GetFeedback(), which a ...
LIVE: Advanced Lighting Map (new default map in Release) has a Skybox the generates Error on Lighting Build
Docs - Samples - Oct 23, 2014Opening the Advanced_Lighting Map, the new default map with 4.5.0 and 4.5.1, the Skybox has 4 UV Channels but all of them have overlapping UVs. WORKAROUND - You can Auto Generate UVs for the Skyb ...
[3ds max] Some geometry will display in all black in Path Tracer renders
UE - Editor - Content Pipeline - Datasmith - Exporters - Dec 12, 2025Reported in SF [Link Removed] Some geometry from 3ds Max will display as all black when viewed in Path Tracer rendering. This effect is visible in both UE and Twinmotion. This was tested with Data ...
Refraction not working for some Android devices
UE - Platform - Mobile - Sep 11, 2015Refraction does not work correctly on some Android devices however it works within the mobile previewer, and on iOS devices. Not working on: 5056_GalaxyS5 SM-G900H (ARM Mali-T628 MP6; 4.4.2) Worki ...
When used with First Loop Start Frame Offset and Use Animation Blueprint, the character will alternate between the specified animation and the reference pose
UE - Anim - Anim in Engine - Jan 30, 2023If you use StartFrameOffset set to 1 or higher in conjunction with the Use Animation Blueprint, the character's animation will be rough towards the end of the section. Specifically, it seems that th ...
UE5.6+ - Mutable - IDPrefix crash when combining Child Objects, Add to Mesh Component and Extend Mesh Section.
UE - Anim - Mutable - Jul 21, 2025So the issue seems to be a combination of Add To Mesh Component and Extend Mesh Section. I've tried this in Epic Launcher 5.6, 5.6 in-house modified engine as well as ue5-main 5.7 from git (editor ...
Making the viewport fullscreen while Application scale is a value other than 1.0 results in a zoomed in/out viewport
Tools - Jan 11, 2017When using Application Scale in the editor, using F11 to make the viewport fullscreen results in an either zoomed in or zoomed out fullscreen version. Note: This same issue occurs when using a comb ...