Outlook: Something Went Wrong Error 80090016

KB ID 0001549


When attempting to open Outlook you see this error;

Outlook Error 80090016

Something went wrong
Your computer’s Trusted Platform Module has malfunctioned. If this error persists, contact your system administrator with this error code 80090016


Note: The this won’t affect users who are subject to MFA (Multi Factor Authentication,) so this can be enabled to solve this problem. 

On the affected machine, run regedit and navigate to;

HKEY_CURRENT_USER > Software > Microsoft > Office > 16.0 > Common > Identity

Create a new DWORD (32 Bit) Entry

  • Name: EnableADAL
  • Value: 0 (that’s a Zero)

Outlook EnableADAL

What does this do?: It disables ‘Modern Authentication’.

Then restart Outlook. (Note: It may re-prompt for a password).

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Author: PeteLong

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  1. “What does this do?: It enables ‘Modern Authentication’.”

    Disables, Shirley?

    Post a Reply
    • Hi Bruce (correct! – need more coffee)
      – And don’t call me Shirley! 🙂


      Post a Reply
  2. Worked a treat with a client battling this issue. Thanks!

    Post a Reply
    • Working perfectly.
      Thank you so much 🙂

      Post a Reply
  3. You made my day. It solved this 3 days pending issue in 10 seconds. That’s great.

    Post a Reply
  4. You saved my life ! Works like a charm !!
    Thank you !

    Post a Reply
  5. I followed the steps, restarted outlook, and am still having the same issue. I wonder what else could be causing the problem.

    Post a Reply
  6. Reg entry worked for me. THANKS!!!

    Post a Reply
  7. oh man worked like charm thanks

    Post a Reply
  8. This may resolve the issue, but I feel like jumping straight into disabling modern auth is not the best resolution.

    Post a Reply
    • Firstly Thanks for the feedback, If you feel there’s a better solution, please post it here for the benefit of others.

      Post a Reply
      • Thanks PeteLong for your hints. Nevertheless I agree with Heywood, it is not a good idea to disable Modern Authentication. And I am affraid it is the one who propose a solution who should estimate the impact and offer other options when it has undesired consequences.

        Post a Reply
        • Guys, Do some research! if a tenant requires MFA/ADAL or OAuth they will have it enabled at an ORG level, so disabling it on a client machine will make no difference whatsoever. If you disable it on a client and it can still connect it was not being used anyway.

          While I appreciate all feedback, think like technicians, if you don’t like a solution, then either find a better one, and communicate it to your peers, or don’t implement the solution that I propose. Remember I’m providing this information for free, for the benefit of the technical community.

          Post a Reply
  9. You saved my day and swett
    Thank you so much

    Post a Reply
  10. You saved my working hours, Thank you very much….

    Post a Reply

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