What server, username, and password are you using to connect? It doesn't look like you have a mysqli connection currently defined and I get a bad password error when I try to use the settings I downloaded from your exhibitions_cx.php connection.
The BETA had an issue where it wasn't showing connection errors properly. I've just pushed a new update live that should give better connection errors.
If you give me the connection information I can try testing with it to see what other issues might exist.