An error prevents the ability to create a cPanel account or add or edit a DNS record to a DNS zone or create Dynamic DNS URLs.
The Dynamic DNS webcalls used to ensure the proper IP is set may leave behind cruft lock files in /var/cpanel/webcalls/ and can cause several issues.
The following is the error seen:
Lock unavailable for 30 seconds: /var/cpanel/webcalls/.lock
The lock file can be removed.
rm -f /var/cpanel/webcalls/.lock
Afterward, that error should no longer be occurring.