SAP Message 6D168 - Some of the selected room types cannot be deleted

Diagnosis
You have selected room types to be deleted which have already beenassigned rooms.

System Response
None of the room types were deleted.

Procedure
Deselect the room types which have already been assigned rooms andpress the 'DELETE' pushbutton again. To delete the room types whichalready have rooms you must first delete the assigned rooms.