After upgrading to Net::FTP version 2.65, I started getting the "unexpected EOF" error message, even though I was using the $ftp->pasv command. To fix it, I changed
my $ftp = Net::FTP->new( $hostname, Debug => 0)
to
my $ftp = Net::FTP->new( $hostname, Debug => 0, Passive => 1 )
Any idea why $ftp->pasv didn't work anymore?

Originally posted as a Categorized Answer.