Seemed ok when I downloaded it using the Print Member Digital Certificate option on the member profile page.
(I'm using Google Chrome, on which Java Script is enabled for the (ISC)2 site)
Someone else reported this same issue here:
Then posted a follow up with the resolution here:
Seems they were newly endorsed and the certificate just wasn't available yet.
Are you newly endorsed?
@zaryab Thank you for your inquiry. @AlecTrevelyan is correct, this is because you are newly endorsed and your cycle start date has not began. I will assume that means your cycle start date is February 1, 2019. On that day, you will be able to download the digital certificate.