Upon returning to work today to a unexpectedly broken PHP script that uses the cPanel API to obtain a list of cPanel accounts, I logged into WebHost Manager and was presented with an Invalid License File error. A little research turned up a few possibilities: invalid hostname resolution, bad system time, license IP address binding, firewall rules, and some other more obscure scenarios. Since I had not performed any changes since the script was last working, the cause of this originally is not entirely clear. But by following some of these steps I was able to resolve the error quickly.
Of course, the obvious thing to check is if the cPanel license is still valid. This is easy with the cPanel license validator. If everything checks out we will need to use SSH to log in as root and check things out. With an invalid license, any Web interface to cPanel will not work.
Here are a few basic things to try first. As root, set the proper system time and run the cPanel license check:
root@server [~]# rdate -s `hostname`
root@server [~]# /usr/local/cpanel/cpkeyclt
You should also check that the hostname resolves properly – any errors or formatting problems can lead to issues.
root@server [~]# host `hostname`
A helpful expired license checklist in the cPanel forums takes troubleshooting further if the above methods don’t help.
If you’re still fighting with problems I’d be happy to help over in the eLanceTalk server admin forums.
Very useful tip there with the /usr/local/cpanel/cpkeyclt, occasional your cpanel will stop working when you change your hostname, run that command and your web hosting control panel will be fine. Amplehosting.co.za