Saving of mission failed! Arma CWA

[Warlordwood93 10]

Everytime i create a mission in the editor and go to save it its comes up with an error along the lines of Saving of mission failed! i have the version 1.99 from steam, hope someone can help its stressing me out!

[Icarus 12]

If you have the key provided with the game, you can try the non-steam version: http://community.bistudio.com/wiki/Arma:_Cold_War_Assault#Download_Mirrors