Are you sure the selected server is not an old server? It sounds very strange.
1. I installed 4.9.10
2. I logged in with admin
3. Via managa-Manage Servers I added an other server with version 4.9.3
4. I closed the client.
5. I start the client again and select the 4.9.3 server.
6. After login I get the message that the server is older, and that it true, it's 4.9.3, not 4.9.10
7. At the login screen I click on the Manage server button and I remove the 4.9.3 server and closed the manage servers window.
8. In the loginscreen my 4.9.10 server is the only server in the list and is automaticly selected.
9. I press the connect button to connect to my 4.9.10 server
10. I get the same message from step 6....
11. If I open the dropdownlist and select the server again (only one in the list) and login again it's fine.
Uses Visualcron since 2006.