PeterMarkwell-0610 avatar image
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PeterMarkwell-0610 asked ·

Teams add-in for Outlook breaking on every Teams upgrade

It seems like every time a Teams update gets pushed out, the Team Add-in for Outlook breaks for 20% of our fleet. The rest are fine and handle the upgrade ok. It's not user specific. Different people are affected each time an upgrade rolls out.

How can we fix this permanently so our Helpdesk is not constantly fielding calls about it?

I'm aware I can fix this on an individual basis by manually running the regsrv32 command to register the appropriate Microsoft.Teams.AddinLoader.dll for the version and architecture of the Office install and ensuing the reg entries for its load behaviour are set. This uses a lot of people resources and smart scripting to workaround the issue for the affected people on an ongoing basis.

Google shows this has been an ongoing issue for 3 years or more. Does Microsoft need to throw some dev resources at Squirrel so it can handle the Outlook add-in upgrade properly?

This is the issue where the Team add-in disappears from the Outlook Options Add-ins list of COM Add-ins. The registration of the new version fails. From the log

2020-06-05-12:25:02.354 AM Addin directory exists. Copy was successful

2020-06-05-12:25:02.354 AM COM registration. Regsvr Path: C:\WINDOWS\system32\regsvr32.exe, Arguments: /s /n /i:user "C:\Users\markwellp\AppData\Local\Microsoft\TeamsMeetingAddin\1.0.20091.2\x64\Microsoft.Teams.AddinLoader.dll"

2020-06-05-12:25:02.724 AM Failed on call Regsvr in wow mode Squirrel.ComRegistrationException

2020-06-05-12:25:02.724 AM ValidateAddinInstallationInternal Entry : HKEY_CLASSES_ROOT C:\Users\markwellp\AppData\Local\Microsoft\TeamsMeetingAddin\1.0.20091.2\x86\Microsoft.Teams.AddinLoader.dll

2020-06-05-12:25:02.724 AM Failed to validate addin installation System.FormatException

2020-06-05-12:25:02.724 AM Failed to install the Teams meeting add-inCOM registration failed. Regsvr Path: C:\WINDOWS\SysWOW64\regsvr32.exe, Arguments: /s /n /i:user "C:\Users\markwellp\AppData\Local\Microsoft\TeamsMeetingAddin\1.0.20091.2\x86\Microsoft.Teams.AddinLoader.dll", ErrorCode: 5, % Message:

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JimmyYang-MSFT avatar image
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JimmyYang-MSFT answered ·

Hi Peter!

Do you mean Teams add-in for outlook will missing after Teams upgrade?

Does anyone else have the same issue in your organization?

In my experience, we recommend you make sure that the add-in is installed and enabled.


As a supplement, you can refer to the following blog to know some factors that may affect Microsoft Teams Meeting add-in for outlook:

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HI JimmyYang-8258

Yes the Team add-in was registered, loaded, appearing in the COM Add-in list per your screenshot and working in Outlook 2016.

Then the latest Teams update, rolled out and the add-in is no longer on the COM Add-in list in Outlook.

Yes approximately 60 users/machines are affected in the organisation. About the same number are affected every time Teams updates, though not the same users/machines every time.

Yes I've read that blog and 112 comments dated from 2018 when the blog was posted to a week ago repeating what I'm saying here. Only manually fix for individual machines is a mentioned in the blog and comments, not a permanent fix. It's an ongoing issue for many Enterprises using Teams.

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MichaelWilloughby-5832 avatar image
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MichaelWilloughby-5832 answered ·

We have the same problem with our organization.
Basically, we fix them as they break- Microsoft support has been pretty worthless in this.
The issue is that it will not register. Go to the %LocalAppData%\Microsoft\TeamsMeetingAddin and find the latest version- which is 1.0.20091.3 Delete the the .dead file and register it again. Sign out of teams, kill it in Task Manager. Kill all other Office programs. Restart Teams, open it - let it run until its done (watch task manager). Then open Outlook.
I have more detailed processes if you need further assistance.
Sometimes you will have to replace the registry keys, others you will not.
But, we have not had one we could not fix manually.
Sadly, you cannot stop the Teams updates that come every two weeks and break it with a version change.

But, as you've stated- Microsoft is completely worthless and doesn't even try to help fix this issue. Its something with their install as the logs would indicate.
Ignore the "experts" here that tell you to look and see if its disabled in Outlook- they are the ones that have no clue what you are talking about.

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