On your pc the mission was created/saved in the 'Multiplayer/Dogfight/Campaign tester/' subfolder, that subfolder is missing on the server.
To fix it:
Either create that folder on the server, and put the mission files in there.
Or re-save the mission to the normal 'Dogfight' folder on your computer, then transfer it over to the server.
Or edit the .list file and remove the 'campaing tester/' folder reference from all the lines in there.
In this case I applied the third option. It should load now.