UDN Licensee (UE4.16) changed rendering settings from MSAA "none" to MSAA x4, resulting in Scene Capture 2D not showing up in mobile preview mode. I have reproduced same results in 4.17 and 4.18.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-51097 in the post.
|Component||UE - Platform - Mobile|
|Affects Versions||4.16.3, 4.17.2, 4.18|
|Created||Oct 11, 2017|
|Resolved||May 30, 2019|
|Updated||Sep 16, 2019|