I had the same exact problem using Power BI desktop as well as at powerbi.com using the Dremio connector (like you, all new versions).
Partial workaround
With Power BI Desktop, once the Dremio Cluster Node had been defined and I hit OK I would get a popup window saying “Unable to connect” and then returning that message.
The workaround was:
- hit cancel at the Unable to Connect window
- Open Data source settings which reveals that the data source was, in fact, created.
- Edit global permissions on the dremio connection and uncheck Encrypt connections
- Open Data source settings again and re-add the same Dremio Cluster Node you tried previously. The global permission for that node should now be in effect so you can hit OK without an error.
This is kludgey, but it worked.
Powerbi.com, however, does not have the ability to make this kind of workaround. So attempting to add a Dremio connector in Powerbi.com resulted in the same error message, but all you can do it accept that it failed and the new connection is discarded.
Current and complete workaround
What I ended up doing is still setting up a DSN on my workstation (and on the local gateway host) to the coordinator using the Dremio driver, but within PowerBI desktop I made an ODBC connection to the DSN which allowed me to connect to Dremio. At powerbi.com I also set it up as an ODBC connection with the connection string just set to dsn=mycoordinatorname and this successfully connects to Dremio.