The recommended answer worked for me:

"The crash in QB running on El Capitan is related to a window left minimized when exiting QB. Some users have had success deleting pref files, but be advised your year version is not supported on your OS.

To delete the pref files

1. Quit QuickBooks if it is running.
2. In the finder hold down the option key and click on Go->Library
3. In the Library window that opens double click on Preferences
4. Drag ALL files of the form com.intuit.quickbooksxxxx.plist to the trash  (where xxxx is a year, like 2015, 2014, 2013, etc - make sure you delete all of them!)
5. Relaunch QuickBooks"


***I was told to prevent it from happening to not minimize any QB windows.  I accidentally did a few times here and there and started haveing the same problem.  So, I followed the step by step instructions again and it took care of it.  I hope this helps!