After attempting to upgrade a few cPanel servers this morning to resolve a phpMyAdmin issue, 50% updated fine, the other half had the error:
The update server is currently updating its files.
Seems one of the update servers is having an issue, if you open the file below and remove the IP – 94.75.231.77
/root/.HttpRequest/httpupdate.cpanel.net
Then run the update again 🙂