I was about to post on the background color of the fieldpicker.
On my machine it was so dark it is hardly usefull.
Small but annoying bug with FMPA 14.04 on OSX 10.10.5
Then I checked my settings in Preferences > General and changed the Appearance color from Graphite to Blue which did the trick and made the picker readable again.
This may be useful to other developers, hence the post.