Got it working. Not sure if something I did or if a server refreshed but;
Turned on beta mode in the general settings
Went to the mods used and turned on beta setting
Clicked to update

This morning I turned it on because I'd read some people are making it work by running it as administrator, but as soon as I arrested it it ran an obvious update (green progress bars on the mods) then offered up the missing "Player" half of the screen. Added player, job done.