Robert,
I suggest the following options. Before trying those, save a pln from each affected projects from the most up to date client, to make it possible to re-share those if anything goes wrong.
1) Restore the previous DNS name of your server, and try to send and receive.
(In BIM Server Control Center keep the Server name on 'Use Computer's name' option)
2) Or, delete Connection.xml file and hopefully your client will find the server. You can find this file in the following location:
•Mac: /Users/[USERNAME]/Library/Application Support/Graphisoft/ConnectionInfo/14.0.0
•Windows Vista/7: [SYSTEM DISK]/Users/[USERNAME]/AppData/Local/Graphisoft/ConnectionInfo/14.0.0
•Windows XP: [SYSTEM DISK]/Documents and Settings/[USERNAME]/Application Data/Graphisoft/ConnectionInfo/14.0.0
3) If none of these helped: re-share the plns
Regards,
Marton Kiss
Chief Product Officer
GRAPHISOFT