Can't see server - "selected profile refers to a database that could not be found"  (4281601)

PA was working ok earlier with this server. Now it can't see it.
The error message is
"selected profile refers to a database that could not be found"
The server does not appear in the list even after choosing 'add new' and refreshing the list.
Other servers appear on the list and can be connected to ok.
 

WORKAROUND
1 Launch Performance Analysis GUI Program
2. Delete the existing connection link for the instance by doing a right click and create new connection link by clicking the Tools button
3. Click the add button
4. Enter the required Instance details
5. Open the drop down list of the "Database:" field
6. Select the needed Instance from the list.