You have to select a table below before you can use the magnifying glass. I'll update the extension to disable that button when it isn't applicable, but that is why you are getting the first error.
The second error implies that the _mmServerScripts haven't been updated to the latest version. Try going to Site->Advanced->Remove connection scripts and then try again. If that doesn't work, you may need to reinstall the extension to get the proper version of the connection scripts. It is possible it was overwritten when installing another extension.