Thanks Shadow! Unfortunately, I don't have that version anymore, but Julia had a fix for me (thank you!).
After some trial and error, this is the solution:
Open strings.txt and go to line 422 or search for "str_ni_server_base". Replace the following URL (in this case http://gs.tyr.lan) with http://gs.nordinvasion.com and save the file. The popup should now be gone and interfere with the editor no more!
PS: I did this in a separate copy of NI. Changes may affect the functionality of multiplayer.
After some trial and error, this is the solution:
Open strings.txt and go to line 422 or search for "str_ni_server_base". Replace the following URL (in this case http://gs.tyr.lan) with http://gs.nordinvasion.com and save the file. The popup should now be gone and interfere with the editor no more!
PS: I did this in a separate copy of NI. Changes may affect the functionality of multiplayer.