I’m referring to the issue being tracked here:
Currently on 4.13.2, was using the HMD Mirror Mode command, now I cannot get a mirror mode screen working when using in the engine or in build. Deleting /saved folder did not solve the problem. I removed all nodes that called the command from project, cleared saved folder, and added this line to my DefaultEngine.ini
[SteamVR.Settings]
WindowMirrorMode=0
and restarted my project.
EDIT:
[SteamVR.Settings]
WindowMirrorMode=0
in the ini was the culprit