[split] Problem with attachments

[malakhi]

hi guys
my board version is mybb 1.8.3
some of users have problem with attachment with latest version of firefox
when try to download attachment they receive (attachment.php ) and attachmented file does not downloaded

sorry for bad english

[.m.]

that could be due to slow internet connection, slow server response or a huge attachment ..
can we have your forum url & a test user account to check the issue