Product and version: FileMaker Pro Advanced 14.0.5
OS and version: OS X 10.11.2
Hardware: Late-2013 iMac 27"
Sometimes it takes 2 attempts to quit FMPA. After the second successful attempt to quit, it is not possible to launch FMPA again without restarting the computer
How to replicate
It's not always possible to recreate. The OnLastWindowClose script trigger may be related to this but the problem doesn't happen every time, even on files that have an OnLastWindowClose script trigger.
Restart the machine