I would verify the information provided in the vdp.log file available at ‘**<DENODO_HOME>/logs/vdp**’ to get more details about the actual root cause of that error in the Virtual DataPort server.
It may also be useful to try changing the logcontroller level to a more granular level like **DEBUG**, which will give you more details. More details about the logcontroller log categories can be found [here](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/appendix/configuring_the_logging_engine/configuring_the_logging_engine). Make sure to change the logcontroller back to ERROR once you have completed testing.
If you still need help and if you are a valid Support User, you may open a Support Case at the Denodo Support Site and the Support Team will help you.
Hope this helps!