After installing Office 365 apps on a personally owned Mac some users get an error that says:

View Only. Your account doesn't allow editing on a Mac. To learn more, contact your admin about your Office plan

This article lists possible solutions to the issue.

First verify that you are using the proper account: 

1. Click Use Another Account and sign in with Eastern email address and password
2. Alternately, click the Activate button in Word and sign in with credentials.

If that does not work, you can attempt to clear credential caches and reactivate office 2016 for the Mac:

You can attempt to clear credential caches and reactivate office 2016 for mac to see if there is any improvement.

1. Open finder > applications > utilities > keychain access and remove the following application passwords.
   • Unknown
   • Microsoft office identities cache 2
   • Microsoft office identities settings 2
   • search for all occurrences of adal in the keychain and remove all those entries if present. 
      
2. Open finder > click go on the top menu bar> go to folder> input the following path: ~/library/containers/
3. Right-click each of the folders below if present, and then click move to trash.
   • ubf8t346g9.ms
   • ubf8t346g9.office
   • ubf8t346g9.officeosfwebhost

If that doesn’t work the last option is to try uninstalling office 2016 for mac completely then re-install and re-activating office 2016.