That usually means you moved your Centova Cast installation to another server, or the domain / IP of your current server has changed.
Anyways, what you should do in order to fix this, is simply re-issue your license. To do so, please follow the next steps:
Login to your client area at centova.com.
Click "Manage Product Licenses" and select your Centova Cast license.
Click the "Re-issue license key" link.
This will authorize the reissuance request on our end. Next, you just need to tell Centova Cast to request a new license. Login to your server via SSH and run:
/home/centovacast/system/runascc/runascc exec ccmanage reissuelicense newhostname.com
Note: The above line may appear word-wrapped, but it should all be entered on a single line. Replace newhostname.com with the new, fully-qualified domain name on which you'll be running the Centova Cast control panel.
The license change will take effect immediately.