When the message above appears when deleting a status, it is because data is still associated with the Status.
A Status may be associated to a Function Group, Responsibility Group, or it may be used by a Room, Item, Occurrence, Product, or a System.
The Status may not be deleted if it has been applied to a Room, Item, etc, if it has an association to a Function Group or to a Responsibility Group.
The Responsibility Group association can be removed in the Items Settings-> Responsibility Groups. The Responsibility Group with the Status association will have to be edited so that the Status can then be deleted.
If the Status has Function Groups applied, they will need to be deleted before the Status can be deleted.