horsthartung,

If this was me, I'd try emailing the error and the seq file (or if too large to email, a link to the seq file at dropbox) to support. Their email address is on the Support page in the main menu above, or better yet try Live Chat.

Live Chat is sometimes a very quick way to get a response and it feels like you've moved to the front of the line.

The section of the last error message you posted says "Access violation at address 009B052E in module 'RealBand.exe'. Read of address 00000210.
Exception address: 009B052E"
This may mean something to the development team, but us users would have no idea what it is .. yet it can sometimes be a key bit of info for the programmers.

That section does say it happened in Realband (sometimes these exceptions happen in a different dll (feature/app/plugin) being run, but this one does seem to point to RB as the issue for you.

I think I recall you saying that Dropbox files you share with your brother seem to have issues quite often, maybe this is related (?)
Any correlation?
If so, this may also be a good clue for support.

Make your sound your own!
.. I do not work here, but the benefits are still awesome