Hi Bob,
I'm also having this kind of problem when connecting PostgreSQL database.
When I edit the Connection String and try to connect, this error appear: "Unknown Authentication type".
Fyi, previously I'm able to connect without editing the ConnectionString, but the problem is I cannot view the data inside the tables correctly. It will show this kind of error:
Error while executing the query;
ERROR: schema "<None>" does not exist
Please help for anyone who know about this.