Hi,
For your scenario, I would check the following configurations to resolve the **“Initialization User Error Cannot initialize user session”** error that occurs during the Data Catalog login:
* If the hostname and port number in the request URL are correct.
* Whether SSL is enabled for the Data Catalog. If so, the default URL would be ***https://<hostname>:9443/denodo-data-catalog?auth=login***.
* If I would be able to connect to the same VDP server (at //localhost:9999/admin) from the same host machine with any other component of the Denodo Platform (e.g. the Design Studio, Scheduler, VDP Admin Tool, etc.).
If all the above configurations are correct, clear the cookies of the web browser and restart the Data Catalog to check if that works for you. Also, try the same once in incognito mode.
If the issue still persists navigate to ***<DENODO_HOME>\conf\data-catalog\DataCatalogBackend.properties*** file and modify the ‘backend.jdbc.pool.validationQuery’ like below:
> backend.jdbc.pool.validationQuery=SELECT 1 FROM DUAL()
Now, save the file and restart the server to check if Data Catalog works fine.
If the issue prevails and you are a valid support user I recommend you raise a new case support case in the [Denodo Support site](https://support.denodo.com/) so that a technical engineer could assist you further.
Hope this helps!!
