# Delete expired files
if($c->{files_expire_access_anon} || $c->{files_expire_access_reg} || $c->{files_expire_access_prem})
{
for my $srv (@$servers)
{
my @files;
if($c->{files_expire_access_anon})
{
my $list = $db->SelectARef("SELECT f.*
FROM Files f
WHERE srv_id=?
AND f.usr_id=0
AND file_last_download < NOW()-INTERVAL ? DAY",
$srv->{srv_id},$c->{files_expire_access_anon});
push @files, @$list;
}
if($c->{files_expire_access_reg})
{
my $list = $db->SelectARef("SELECT f.*
FROM Files f, Users u
WHERE srv_id=?
AND f.usr_id=u.usr_id
AND usr_premium_expire AND file_last_download < NOW()-INTERVAL ? DAY",
$srv->{srv_id},$c->{files_expire_access_reg});
push @files, @$list;
}
if($c->{files_expire_access_prem})
{
my $list = $db->SelectARef("SELECT f.*
FROM Files f, Users u
WHERE srv_id=?
AND f.usr_id=u.usr_id
AND (usr_premium_expire IS NULL OR usr_premium_expire < NOW())
if $c->{dont_expire_premium};
AND (usr_premium_expire IS NULL OR usr_premium_expire < DATE_ADD(NOW(), INTERVAL -30 DAY) )
if $c->{dont_expire_premium};
push @files, @$list;
}


next if $#files==-1;
print"Have ".($#files+1)." files to delete from SRV=$srv->{srv_id}...\n";
$ses->DeleteFilesMass(\@files);
print"Done.
\n";
}
}

{
my $list = $db->SelectARef("SELECT f.*
FROM Files f, Users u
WHERE srv_id=?
AND f.usr_id=u.usr_id
AND (usr_premium_expire IS NULL OR usr_premium_expire < NOW())
if $c->{dont_expire_premium};
AND (usr_premium_expire IS NULL OR usr_premium_expire < DATE_ADD(NOW(), INTERVAL -30 DAY) )
if $c->{dont_expire_premium};
push @files, @$list;

it doesn't look like you're selecting any columns from Users because you've only specified f.* and nothing for Users

Smart arse comments aside, it looks like you haven't terminated the string constant for the database query.
The other queries have a " at the end of the query where the rest of the code continues.