Hi... I'm trying to upload some Counter-Strike Source map files (bsp files) using filezilla, and I keep getting an error;

553 Filetype not allowed. File surf_greatriver_v4.bsp won't be saved.

I've tried with other maps too and same message.

So if anybody can help me in any way it would be much appreciated!

Um... I'm no genius so I'm not sure. But it's saying that BSP file types aren't allowed. Try Zipping all the maps together (or each map in it's own zip file) - Right click on the map, hit send to, compressed (zipped) folder.. and then upload that to filezilla that should work.

.bsp Probably isn't on the allowed file list, however you can request it to be allowed here.