By accident I have created a calendar with a colon in there. Now it shows in the calendar interface at the same level as Calendars . Below there is the screenshot. The part before the colon is at the same level as Calendars, the part after the colon site below.
It is not possible to delete this item as it is the only item in this group (it deletes, than, a little while later comes with an error message: An error occurred, unable to delete the calendar) and the item is back.
The part at the level of Calendar cannot be deleted, ie there is no option to do so.
Forgot to add: e/os 3.2, working on a desktop (linux)

