Hi Albert
If you contact the support team support@servicedeskplus.com they should be able to provide you with a query to blank out or update the group in the relevant tables so then you can delete it.
Due to data integrity if there are workorders against a group you will not be able to delete it - it should become greyed out so its not longer available for selection.
The group may also have technicians, CI mappings and other items against it.
If you contact the support team support@servicedeskplus.com they should be able to provide you with a query to blank out or update the group in the relevant tables so then you can delete it.
Andrei