- clear the keychain in mac os referring to the article below:
resetting your keychain in mac os x
- try a total reset of all office 2016 activation keys.
a) click go on the start screen of your mac and choose go to folders in the drop-down options;
b) type ~/library/ in the open window and click go;
c) find all ubf folders and move it to trash, then empty the trash bin;
d) restart your mac and reactivate your office
note: before performing that, i’d like to know whether you have outlook & onedrive for business configured. if yes, you need to reconfigure them after performing the following action, so backing up for your files is neededin case of file missing.