Could reproduce this with Qt-Creator from our latest snapshot (5.6.2, macOS) - it's enough to press Cmd-O in Qt-creator, file dialog pops-up but after that I could do nothing - neither using keyboard, nor mouse - I can not select any file/folder in this dialog. Unfortunately, not always reproducible (after I restarted Qt-Creator - it works now). Also I saw this with 5.7.0 and some user application (again, it was a problem with open file dialog). Standard button in this dialog ('Cancel'/'Open' were grayed and inactive - if it helps )