Teams meeting missing from classic outlook calendar

Question

Teams meeting missing from classic outlook calendar

Randy Visser 0

When I first got to the user the add in was disabled for causing a crash in outlook. I reenabled it and got it out of the disabled add ins page.

The comm add in for teams shows in the com add in page.

I have tried the following:

Reregister the add in loader

Uninstalling the add in numerous times for it to auto reinstall.

A full online repair of M365

Reinstalling outlook and teams multiple times.

When going through the microsoft troubleshooting steps theres a regedit step when trying to navigate to "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\Outlook\Addins\TeamsAddin.FastConnect" Outlook was not an option in the Office section.

I made the registries to fill in all the way to teamsaddin.fastconnect and populated it with the correct keys and dword.

After doing this I was able to add the teams meeting button to the ribbon by customizing but it is still greyed out and not able to be pressed.

Please advise

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2 answers

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Answer 1

Hornblower409 10,305

Teams Add-In installed but not working

Possible fix from Reddit - A Teams configuration file is missing and without it the meeting Add-In fails.

[External Non-Microsoft Site] https://www.reddit.com/r/Outlook/comments/1ujm2gw/comment/ouplsfg/

The file app_switcher_settings.json is missing from: %LocalAppData%\Publishers\8wekyb3d8bbwe\TeamsSharedConfig

Copy the json file from a known-good machine and paste it into the TeamsSharedConfig folder.

Contents of the file that worked for me were: {"defaultApp":1,"cohort":"","webAccountId_AAD":"","cohortStage":"","userId_AAD":"","previousT1MachineId":"","previousT1SessionId":""}

Then close both Outlook and Teams, launch Teams first, then Outlook.

For additional information and the steps to create the json file from scratch, see the original Reddit post.

Mr Gigs 0 Reputation points

2026-07-02T13:24:42.8266667+00:00

This fixed the issue for me, thank you! For those of you who don't have another machine to grab from, attached is the file that worked for me, just remove the .txt file extension from the end - it wouldn't let me upload a json file here. app_switcher_settings.json.txt

Answer 2

Dear Randy,

Good day, and thank you for the detailed description of your issue.

I would like to let you know that there is an ongoing service incident affecting multiple Outlook users on Classic clients, which aligns very closely with the behavior you have reported. The issue ID is TM1402778.

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The developer team is aware of this issue and is actively working on a resolution to roll out a fix as soon as possible. For further details, please review this incident report in the Service health menu in Microsoft 365 admin center. If you are the end-user, please contact your organization's IT administrator or help desk. They can verify the status of the service incident for your tenant and submit a technical support ticket to Microsoft to prioritize a fix. If you don't know who your IT administrator is, please refer to this article: How do I find my Microsoft 365 admin? - Microsoft Support

I sincerely apologize for the inconvenience this has caused. If you have any additional questions or further information to share, please feel free to let me know. Thank you for your patience and understanding. Please let me know if you need anything else.

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