Apologies for the inconvenience, there is an issue with 'Download Center for FPGAs' portal, we are working on it & we`ll get back to you soon.
May I know, which Quartus Edition(Std/Pro/Lite)& Version are you using?
This case was escalated to next level. We currently reported internally for further checking. Once we make progress, we will update you.
Intel Customer Support
We got this issue fixed. Clear your browser cache and cookies and then reopen the browser for login attempts.
You should be able to download the package after.