While trying to upgrade cpanel to new version was getting error
FATAL: Failed to download updatenow.static from server:
The issue was due to corrupt RPM
I used the below fix to resolve this issue
Now move the original RPMs to the new folder
mv /var/lib/rpm/__db* /root/old_rpm_dbs/
Finally rebuild the RPM database
Now you can force an update of the cPanel server and it should work again.