after a long time of testing I can say the mixed calendar files appears only with the activated function "Keep offline copy".
With this activated function sometimes Rainlendar crashes at start on my Notebook and if I check the calendars after this the files are corrupted.
Since months I'm testing this and the only problem I've found is the behaviour of Rainlendar with offline copies.
During the test I changed the App for synchronizing with Android. I'm syncing now with "Calendar Sync" and the problems are the same like with "ICSSync".
Has anyone an idea what happens? I'm sure I'm not the only one who is using the offline copies...
Many thanks in advance for some help!