[Stephen]

... I change host name server1.xxx.xxx to ip of my server 198.100.144.XX. after that change I have lost access of cpanel.
...
Your license could not be activated because:

Cannot Read License File

1. First, go to verify.cpanel. net/ and enter the public IP address of this server to make sure it is licensed.
2. If licensed, try running /usr/local/cpanel/cpkeyclt from the command line as root.
3. You'll also need to make sure that port 80 is open to contact our license server and that your server's hostname is a FQDN.

... .

Just to clarify you changed the hostname from server1.xxx.xxx to the ip address of 198.100.144.xx in WHM (so setting the ip address as the hostname).

If this is the case you probably need to change it back to the FQDN (server1.xxx.xxx) as per point 3 above of not being able to read the license file.

[Razakel]

Have you actually purchased a cPanel licence?

[diljani]

I have an ovh server. Some days before I just login in my WHM and I change host name server1.xxx.xxx to ip of my server 198.100.144.XX. after that change I have lost access of cpanel. When I login root I got this error screen.

Thank You for installing cPanel & WHM.

In order to access the interface, you will need to make sure that the software license on this server is active and installed.

Your license could not be activated because:

Cannot Read License File

1. First, go to verify.cpanel. net/ and enter the public IP address of this server to make sure it is licensed.
2. If licensed, try running /usr/local/cpanel/cpkeyclt from the command line as root.
3. You'll also need to make sure that port 80 is open to contact our license server and that your server's hostname is a FQDN.
I verify my ip is active on cpanel, port 80 is open and I try to login SSH root but I remember I block SSh access of my server for security purpose.

I tried a lot to submit tickets to ovh and cpanel but resolve my issue.

I also try OVH server rescue mode loging recue SSh root, mount drive chroot.
run command /usr/local/cpanel/cpkeyclt
got msg...
root@rescue [/]# /usr/local/cpanel/cpkeyclt
Updating cPanel license...Error, do this: mount -t proc none /proc
Done. Update succeeded.
Building global cache for cpanel...hostname: Unknown host
Done

unable to resolve issue.

Now I want help if anyone can help me.