The latest version (v3.5.1) refuses to connect to my RedHat server, even though all previous versions of FileZilla did.
Reading some of the threads around the web, the developers decided to use the MLSD command (to get a directory listing) and it seems to cause no end of problems.
They seem to insist that MLSD is a standard command and the people should change their FTP servers instead.
Perhaps those devs should extract their cranium from their anus, instead of telling people to change their (perfectly good FTP servers. We use ProFTPD)
That rant aside, the way to overcome this problem is to not use passive mode.
Use the File/SiteManager menu to find the entry you want to connect to and, under TransferSettings, set the Transfer mode to Active.