Hi. I'm not sure if it exactly the same issue but it sounds very like the problem I had. See the earlier post set off by me.

Somewhere towards the bottom of the discussion you'll see this message from me, detailing how I (accidentally) solved the issue. May not help if you haven'y got an earlier copy of Realband...

Hi all.
Now, it will take greater minds than mine to explain this but

...having totally disabled User Account Control and still having the problem I became unconvinced the issue is anything to do with administrator level access but probably more something like Realband is stuck in a partial, unfinished rebuild of the Stylepicker.

After trying everything else I overwrote Realband 2016 with an installation of Realband 2015. (Just Realband, I left BIAB 2016 untouched). Hey presto, Realband 2015 did a longer rebuild on first opening and then worked fine.

I then upgraded again with a re-installation of Realband 2016 (making sure I installed always as the administrator) and...everything works fine.

User Account Control is still active but I'm running the program as an administrator.