Microsoft has disclosed that Mac Office 2016 apps will frequently crash when run under OS X 10.11. Although Microsoft released an updated to Office 2016 yesterday, it did not resolve these issues. Microsoft posted this today “This update doesn’t address the issues experienced by Office customers with OS X 10.11 El Capitan. We are actively working with Apple to ensure resolution with the next update of OS X 10.11 El Capitan.”
>>UPDATE: The OS X 10.11.1 update fixes this issue.

Right off the bat a major bug was discovered with Mac Office 2011 and OS X 10.11, where if Outlook is setup to access an Exchange account, it will hang Outlook whenever attempting to access the server. This has been resolved with an Office 2011 14.5.6 update released last week.