As said, the renaming of calendars in korganizer does not work here. I can give a calendar another name than "Calendar Folder" but that does not last over an akonadi restart nor is it shown when creating a new event in the calender selection field. All 5 Calenders are named "Calendar Folder" than I can only guess which one is correct.
I am using openSUSE Tumbleweed with latest KF5, Plasma and KDE Apps.

Anybody an idea how to solve this issue?

robsn81 wrote:As said, the renaming of calendars in korganizer does not work here. I can give a calendar another name than "Calendar Folder" but that does not last over an akonadi restart nor is it shown when creating a new event in the calender selection field. All 5 Calenders are named "Calendar Folder" than I can only guess which one is correct.

Saving the folder properties was broken in kmail, maybe this is related?
Should be fixed in 16.12.2 then.

I am using openSUSE Tumbleweed with latest KF5, Plasma and KDE Apps.

Not really.
The latest KDE applications (16.12.2) have just been released two days ago, and are not in Tumbleweed yet...

Should appear in a few days though, the packages have been submitted already.