Your GameServer uses the "FileZilla FTP Server" for FTP Transfers:
Connecting to ***, Port 21 (#1)
Connected. Waiting for response.
220-FileZilla Server version 0.9.23 beta
Currently our system is not allowed to download the logfile from your gameserver. We always get an error that we are not allowed to access the logfile, because another process (the COD4 GameServer) is using this file at the moment:
RETR games_mp.log
150 Connection accepted
550 can't access file.
You or your serveradmin has to adjust the Settings of your Filezilla FTP Server, and allow us to download the logfile even if the COD4 Gameserver is using it right now ...
I don't run a Filezilla Server, but according to the thread posted above you just have to visit the "Settings Page" of Filezilla and then under "miscellaneous" should be a tickbox for
"Allow transfers of files opened by another process", which you have to enable, so that we can finally download the logfile