1. You are out of licenses on your account.  This will happen even if the appliance you are trying to license has been previously licensed on the account.  The licensed device is tracked internally by a set of unique identifiers.  If that set of identifiers has changed (which will happen if you reinstall the system from scratch), the licensing server will see that appliance as brand new.   
2. Your system was previously licensed with another License Key and you are trying to use a different one.  

Contact technical support in order to delete the old licensed device and free up the license.  Before you contact support, please have the following information ready:

1. Your 16-digit alphanumeric license key
2. A copy of the DSSEED.tgz file (available from the Licensing Details page within the GUI)

If the Security Analytics appliance was previously licensed and you are trying to license the appliance with a different license key, you must first completely delete all remnants of the old key on the appliance.  This requires CLI access as root from an SSH session.  DO NOT perform these steps if your license key has not changed.  Performing these steps with the same license key that was used previously will consume an additional license in the system.

1. Log in as root from the command line interface (CLI)
2. Run the following command.  It is one large command, so make sure you copy the entire line.  Be aware that you may get permission errors, which is normal.  Ultimately you should see several DELETE responses from running the command.  Typically you will see 3 DELETED items.  It will not damage the system if you run this command multiple times.

   1. echo "DELETE FROM meta WHERE name='deviceId' OR name='accountId' OR name='licenseKey';" | su -c "psql dsweb" postgres && rm -f /etc/solera-license.dat

3. Reboot the appliance using the 'reboot' command
4. After the reboot, attempt to license the appliance again with the appropriate license key