Recently, there is an issue with the installer certification and this will be fixed in the next Quartus installer release. I am not sure if this might be the cause as the error message should stated :
Test download failed with certificate error: SSL certificate problem: unable to get local issuer certificate (curlcode 60)
However, you will need to apply the workaround below; otherwise, the installer will display the error shown above.Please let me know how it goes after you have applied the workaround.
Workaround: Kindly download the attached cacert.pem (unzip it first) to your machine, and from the installer settings, please specify to the new cacert.pem and test the connection. You should be able to download it.