If you run into issues with Outlook after the upgrade, start with disabling your add-ins.
Only a single version of Outlook can be installed at a time on a computer.
Note: Even when you are using the 32-bit edition of Office 2016, some add-ins might not be compatible yet with Office 2016.
You can check with the vendor of the add-in to verify its compatibility.
To prevent a Contact Card opened from the Search People box from closing when you click anywhere else, you must click the Pin icon in the top right corner.