incompatible_archive; PCLZIP_ERR_BAD_FORMAT : Unable to find End

Error: incompatible_archive => PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

im trying to update my own plugin from my site,

when i give it a direct link to the new zip file alls well,
but when i want to cloak it , it gives the above error

https://domain.com/pluginlink/{username}/plugin.zip

and im intercepting ( on wordpress ) on ‘init’, and checking if file exists, and then using readfile.

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
readfile($file);