I don't know which version of Transfer you have. I have the first one and I've kept it rather than upgrade to the more versatile but complicated Browser. All I want to do is import media from my S x S cards shot on the EX 1. This always worked perfectly until I upgraded my OS to Mountain Lion. Following which I have to fiddle about rather more (ignoring an ominous warning) but do still manage to get the media in to Media 100.
Your screen shot seems to indicate the absence of a driver, have you managed in the past to import the media with exactly the same set up as you have now? If so that a puzzle. You could post Ian Cook of Sony on the ex forum.