You are trying to remove a Discover server from the Data Loss Prevention(DLP) Enforce Server and getting the following error:
Red Banner Error:
Server server_name cannot be deleted because at least one Discover Target is assigned to it. You much first assign this Discover Target to another server or delete it.
Go to the Discover Target list and move or delete any targets assigned to the Discover server you wish to delete.
Note: To successfully delete a Discover target all associated incidents must be deleted as well.