The error you are getting may occur due to one or more missing properties in the VDBAdminConfiguration.properties file located at <DENODO_CLIENT_HOME>/conf/vdp-admin/, if the error is on the client side.
If the error is one the server side, you can find the configuration properties file of VDP server at <DENODO_HOME>/conf/vdp/VDBConfiguration.properties. To find a more verbose error, I would look into vdp.log file located at <DENODO_HOME>/logs/vdp/.
Additionally, I would do the following checks:
1. In the Denodo Platform Control Center, ensure to specify the correct IP address or a hostname in the “Denodo Control Center>Configure>JVM options>RMI Host>Virtual DataPort Server”.
2. Launch the tool with administrator privileges by right-clicking on the Denodo shortcut and click “Run as administrator”.
Hope this helps!