For problems with launching ‘Pro Tools First’ I found that a ‘first time setting’ of the ‘Playback Engine ‘ can give problems.
(This could be because there’s not yet (Dec 02, 2016) an officially version of Pro Tools First for OS X 10.11.6). [check]
There is a solution that works for me.
Lees verder [solution] Pro Tools First on MacBook Pro (mid 2010) with OS X 10.11.6 – El Capitan