Had a head scratcher - thought I would share my experience just in case someone else runs into the same thing.
My transition to Cubase 8 was rough. I have some older plugins (Powercore, and a few others) that now throw errors when being scanned at startup. Cubase 8 doesn’t like the errors, or at least the error dialog box, and crashes. Note that there is something in the Knowledge base that kind of covers this, but…
After rebooting, my MR816 was gone - not just from Cubase, but from my entire system. Eventually, on a hunch, I tried deinstalling/reinstalling the drivers, and that fixed it.
Unfortunately, it took some doing to figure out what all the offending plugins were, so I had to do this more than once. And every time, the MR went away. It was absolutely repeatable on my system.
I guess that’s what you get for being with Cubase since SX1.
Oh, and unrelated to the MR, but frustrating - if you start Cubase 8.0, and do stuff in the Drivers menu (I was setting up my plugins and remotes), then close it, it will hang. 100% reproducible. If you load a project, or even create an empty project before closing, then it’s fine.