Every time I try and join Gulag or any of the other maps in Multiplayer, I get an error message that I can't read because it won't allow me to pull it up. Help!

I guess you are missing the SP maps. ItВґs better when you are using the whole game or ask Google

change graphic settings to manual i think and put everything to normal.

press windows key or ctrl and escape and you can read it in console , better off with full game than a mp rip as it contains all the sp map files