>> Check if any invalid node is listed in the Spotfire database by running the below command, refer below screenshot.
<Spotfire Server install dir>\tomcat\bin\config list-nodes
>> If you see any nodes which are invalid (Has Valid Node ID = No), you can delete the nodes by using the 'config delete-node' command.
e.g.
<Spotfire Server Install>\tomcat\bin\config delete-node --id=<id of the node that should be deleted>
>> Restart the Spotfire Server service and Node Manager service.