issue with Microsoft Teams meeting add-inns

Question

my outlook verison is : 1.2026.303.100

when i enable the "Microsft Teams meeting Add-in for Microfost Office", my outlook does not even start.

pls help with solution urgently

thanks.

---

Mod moved from : Outlook | Windows | Classic Outlook for Windows | For business

Answer 1

Hi @Sharma Bharat, 

Good day, and I appreciate the detailed description of your issue.  

I acknowledge how being unable to open classic Outlook can interrupt your day to day work, and I am grateful for your patience while Microsoft addresses this.  

Microsoft has confirmed an active Microsoft 365 advisory, EX1254044, categorized as a service degradation in Exchange Online, where some users may be unable to use classic Outlook when the Teams Meeting Add in is enabled. In this event, impacted users may experience crashes in classic Outlook or may be unable to launch the application after enabling Microsoft Teams Meeting Add in for Microsoft Office, which matches the behavior you described.  

Regarding the cause, Microsoft has identified a code issue in the Teams meeting add in update included with Microsoft Teams version 26043.2016.4478.2773, which is creating a compatibility issue with classic Outlook and resulting in functionality issues.

  

For your reference: Service health - Microsoft 365 admin center 

Note: Access is limited to Microsoft 365 Global Administrator. Please contact your IT admin if you don’t have access.  

Microsoft has also confirmed that a fix has been developed and will be included in Microsoft Teams version 26058.712.4527.9297, with deployment beginning on March 30, 2026. The next update is scheduled by March 30, 2026. The steps below are the most effective mitigations while the service fix is deploying. 

First, please try opening Outlook in Safe Mode and temporarily disabling the Teams add in so Outlook can start.  

• Hold the Ctrl key while launching Outlook to start it in Safe Mode.  
• Select File, then Options, then Add ins, and next to COM Add ins, select Go.  
• Clear Microsoft Teams Meeting Add in for Microsoft Office, select OK, and then restart Outlook normally. 

Next, please confirm your Microsoft 365 Apps are fully updated, because Microsoft’s guidance for this symptom includes updating Office to the latest build when Outlook is crashing.  

• If Outlook will not open, please open Word.  
• Select File, then Account, then Update Options, and then select Update Now.  
• Restart the device after the update completes, and then test Outlook again with the add in enabled.  

If your workflow requires the Teams add in immediately, Microsoft has confirmed that Microsoft Teams version 26032.208.4399.5 works successfully with classic Outlook, and they recommend requesting a temporary reversion through support while remediation continues. In that case, please contact your IT support or Microsoft support representative to request a temporary rollback to that Teams version.  

For your reference, that you can concern:

• Classic Outlook crashes and opens in Safe Mode starting March 12 2026.  
• Resolve issues that affect the Teams Meeting add-in for classic Outlook - Microsoft Teams | Microsoft Learn 

Since you shared that your Outlook version is 1.2026.303.100, if the issue continues after the steps above, a few details will help narrow down the scenario quickly.  

Which Outlook client are you using on the affected device, classic Outlook for Windows, the new Outlook for Windows, Outlook on the web, Outlook for Mac, or Outlook mobile.  

What Microsoft Teams version is installed, and did this start right after a Teams update or only after enabling the Teams Meeting Add-in.  

When Outlook fails to start, do you get a Safe Mode prompt or any error message, and if possible, can you share a screenshot of the message or the approximate time you first noticed it 

Thank you again for your time and for raising this important usability concern. If you have any further questions or need additional assistance, please don’t hesitate to reach out.   

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment”.     

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread. 

Answer 2

Use the following steps to fix Outlook crashing when the “Microsoft Teams Meeting Add-in for Microsoft Office” is enabled.

1. Confirm the add-in state in Outlook
   Because Outlook won’t start with the add-in enabled, first start Outlook in safe mode so the add-in is not loaded:
   • Press Windows + R, type:
     outlook.exe /safe
     and press Enter.
   • Go to File > Options > Add-ins.
   • At the bottom, next to Manage, select COM Add-ins and choose Go….
   • Make sure Microsoft Teams Meeting Add-in for Microsoft Office is visible. If it is in Disabled Application Add-ins, re-enable it later after completing the steps below.
2. Make sure Teams and Outlook are running in the same context
   If one app runs as administrator and the other does not, the add-in can fail and crash Outlook.
   • Close Outlook and Teams.
   • Right‑click the Outlook shortcut > Properties > Compatibility and ensure Run this program as an administrator is unchecked.
   • Do the same for the Teams shortcut.
   • Apply the changes.
3. Restart in the correct order
   • Start Microsoft Teams and sign in.
   • Then start Outlook normally (not in safe mode) and check whether Outlook opens without crashing and the Teams Meeting options appear.
4. Repair the add-in registration (reregister the loader)
   If Outlook still crashes when the add-in is enabled, reregister the Teams add-in loader DLL:
   1. Exit Outlook.
   2. Exit Teams.
   3. In File Explorer, go to:
      %LocalAppData%\Microsoft\TeamsMeetingAddin
   4. Open the subfolder that matches the version number (for example, 1.0.23334.11). If multiple, choose the one with the highest build number. Copy this folder path.
   5. Open an elevated Command Prompt (Run as administrator).
   6. Run the appropriate command for the Office bitness:
      • For 64‑bit Office:

                %SystemRoot%\System32\regsvr32.exe /n /i:user <path>\x64\Microsoft.Teams.AddinLoader.dll
        

      • For 32‑bit Office: use the corresponding x86 path (as documented in the same article).
   7. After the command succeeds, start Teams, then start Outlook and test again.
5. Verify Outlook and Teams versions and updates
   • Ensure the Teams desktop client is installed (not just the web version).
   • Confirm Outlook is 2016 or later and fully updated.
   • Apply any pending Office/Outlook and Teams updates, then repeat steps 2–4.
6. If Outlook still will not start with the add-in enabled
   • Leave the Teams add-in disabled in File > Options > Add-ins > COM Add-ins so Outlook can start.
   • At this point, tenant‑level or profile/registry issues may be involved (for example, corrupted profile or policies). Engage the organization’s IT admin or open a support case so they can follow the deeper admin guidance in the referenced articles (group policy, registry, and tenant configuration checks).

These steps align with Microsoft’s documented troubleshooting for when the Teams Meeting add-in is missing, disabled, or causing Outlook startup issues.

---

References:

• Troubleshoot the Teams Meeting add-in in Outlook for Windows
• Resolve issues that affect the Teams Meeting add-in for classic Outlook
• Understanding the Microsoft Teams Meeting Add-in for Outlook: Eligibility, Issues, and Troubleshooting
• Admin - Authentication requirements and functionality of the Teams Meeting add-in in Outlook