Sometimes the SERVER key may become invalid if you change the computer name or upgrade your hardware. Changing the computer name is not advisable unless all the licenses have been returned. Most common reason for invalid SERVER key, then, is hardware upgrade that changes the server code (server id).

To install a new valid SERVER key for your computer, please follow these steps:

1. Open the License Administrator (hkey)
2. Select File -> Install Licenses
3. Log in
4. In the dialog box click on the "Licenses" tab
5. Select the checkbox to reinstall the SERVER key
6. Press Install button

This should reinstall the new SERVER key for your computer.