License File Expired Solution
If your cPanel license has expired, your cPanel/WHM interface will become inaccessible. Here are the steps to resolve this issue.
Renewing Your License
First, renew your cPanel license through your hosting provider or directly from cPanel at http://store.cpanel.net/.
Updating the License File Manually
After renewing, you need to update the license file on your server. SSH to your server as root and run:
/usr/local/cpanel/cpkeyclt
This command will fetch the new license file from cPanel's servers and update your installation.
Alternative Update Method
If the above command doesn't work:
rm -f /usr/local/cpanel/cpanel.lisc
/usr/local/cpanel/cpkeyclt
Checking License Status
To verify your license status, run:
/usr/local/cpanel/cpanel.lisc
Or check the cPanel license verification page at http://www.cpanel.net/apps/verify/.