Q: Mac Sandbox NOT Granting Access to Files, Even Local Files

Mac OS X El Capitan 10.11.6.  Office 2016.

I have an Excel workbook that has VBA code behind that opens other workbooks.  The code worked fine before I updated to El Capitan 10.11.6.  Now it prompts if I want to grant access, but DOES NOT GRANT ACCESS even when I press the "Grant Acccess" button.  By the way, before the update the "Grant Access" button was blue.  Now it is gray, for what it is worth.  Help anyone?!  Thanks.