I have problems too. I reinstalled Windows, installed Rainlendar Pro 2.10 x64 (with license) and when I restore my backup file, many different problems occur. I tried uninstalling and reinstalling but still happen.
I guess it's got to do with some conflict with Google Calendar settings or so.
So, the data are there, sort of restored, I can see the appointments and to dos but for example when I write a new event I get this window:
What can I do?
EDIT: Maybe this is the problem? When I open Google Calendar it says that the service is not available at the moment.
EDIT 2: OK, seems to be fixed. I deleted the Google Calendar and added it again with the password again. Also Google Calendar on web seems to be working fine again.