Can also be displayed:
This is an error with the CTL file, it does not match the license.dat on the server
Check the CTL is the latest one issued to you. If you have recently changed license server machines, you will have been issued a new CTL for this new license server.
If you are using an older version of LDRA and we did not issue you a new CTL for this version when you changed license server, request a new CTL for this version.
If you have recently changed servers, make sure the Environment Variable has been updated to the new server.
If you have added a domain to the server name in the license file, e.g. hostmame.ldra.com, you may need a new CTL file.