Does nothing

This app unfortunately does nothing. Double clicking on a downloaded winmail.dat file, or clicking on one in an email just opens the app window. No matter what I do, I cant get it to open the original attachment. Not sure whats different about me as others have obviously got it working 100%. I’ll be asking Apple for a refund. Yosemite, 2011 MBA.

zoneout9 about Winmail Viewer - Open dat file