Now this doesn't quite make sense to me but on my server when I change the map to mp/ffa3 (tatooine) It gives me...
Error:
.... 1 Missing Sound Sets!
(see above)

and that's it...but what I don't get is that on other servers I can go to tatooine fine without any troubles. I've looked all over and haven't found anyone with the same problem thus no solution, please help.

you have too many pk3 in your base folder

so the game does not succeed in loading all of them

when you join a server, some of the data belonging to the unloaded pk3 are requiered...

so you have error

solutions ==> remove all uneeded pk3 from your base folder