You need to zip or rar the file before attaching.
Okay thanks for clarifying this reuploaded.
There is still no attachment. Why don't you upload it to a file sharing site and share the link?
Here is a download link mega.nz/file/S5pAhY5Y#LtnxOL-mKqg_lCl2MaE5e1iVWGGSM-qa8vLBW7gq0w4
I have no idea why the attachment isn't showing up placed it in the Attach CoSMOS file box with the paper clip selected the file showed up there but when I go to post it doesn't show up.