Fal - you need to upload using a 3.06 client. If you upload with your patched 3.08 client you crash the server.
If you have upgraded your install and didn't back it up first the only way you'll be able to do your turn is if you reinstall Dom3 to a different folder, upgrade to the 3.06 patch and do your turn (probably want to copy the map over from your 3.08 install). Alternatively, if you don't want to mess with this you can just stale this one turn
Edit: The turn will host in about an hour, at which point I'll upgrade the server to 3.08