used to click on user missions download and it works. Download button no longer works

[redmantab]

I've downloaded missions before from the user missions area on the website. Now, when I try to download many different missions when I click the download box it doesn't open up a zip file or place to save.

 

It literally opens up this small black box for a super quick second that I can barely see....and nothing happens. This is with chrome and IE. What on earth am I doing wrong?

 

Thank you!