Office 365 Crashes or Activation Errors on Mac OS


Mac OS / Office 365


Attempting to activate or use Office 365 on Mac and a component crashes or you receive the error, "No credentials / The system requires that you sign on to a valid account. The error code is: 0xD000000C" or "Unknown Error. An Unknown error has occurred. The error code is: 0x0"


Activation Error

  1. Make sure the internet is working on the Mac 
    1. You can do this by opening your internet browser and going to
    2. If the page loads, your internet connection is working
  2. Quit out of all Office apps
  3. Run the License Removal Tool
    • Izzy-managed (University) computers:  Go to Applications --> Utilities --> Service Provider Support, find the "Office 365 License Removal Tool" and click the "Remove" button
    • Personally-Owned computers: Download and run the License removal tool to remove all the Office keychain entries
  4. Restart computer
  5. Start any Office app again and follow the activation prompts

If you've signed in to your Mac using a Network account such as an Open directory account, this error may occur because Office for Mac can't write your credentials into the keychain as it is "read-only."

  1. If you are signed in with a network account, sign out and sign back in with your local user account
  2. Try activation again
  3. If you don't have a local user account, you must create one:
    1. From the Apple menu, select System Preferences > Users & Groups
    2. Select Click the lock to make changes, and type your password. Select Unlock
    3. Select +, and then fill in the new account information, and then select Create User
    4. Log into your local user account and activate again

Other Office 365 Crashes 

If you have a University-owned Mac and are having problems with Office 365 crashing, contact your local IT support or the ITS Service Center. The instructions below are for personally-owned Macs only

  1. Personally-owned Macs
    1. Download tool from
    2. Run tool and choose check next to any application that is causing issues and install

Additional Information

For the most up-to-date information, please visit the following site: Error 0xD000000C when activating Office for Mac.

Need additional information or assistance? Contact the ITS Service Center.

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Article ID: 3580
Tue 9/1/20 1:52 PM
Mon 8/29/22 1:54 PM

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