Outlook for Mac Crashing After Update to Version 16.88.1

Question

Outlook for Mac Crashing After Update to Version 16.88.1

DHANASEKAR NELLAIAPPAN 0

The Outlook app for Mac is crashing after an update to version 16.88.1 (24082514) on a MacBook Air M2.

Attempts to auto-update result in a crash with the following error details:

Process:               Microsoft Outlook [40567]  
Path:                  /Applications/Microsoft Outlook.app/Contents/MacOS/Microsoft Outlook  
Identifier:            com.microsoft.Outlook  
Version:               16.99.1 (16.99.25072013)  
Code Type:             ARM-64 (Native) 

Dyld Error Message:

Crashed Thread:        0  
Exception Type:        EXC_CRASH (SIGABRT)  
Exception Codes:       0x0000000000000000, 0x0000000000000000  
Termination Reason:    Namespace DYLD, Code 1 Library missing  
Library not loaded: @rpath/libmbupdx2009.dylib

Referenced from: <6EB61E81-3A63-3961-882B-AE890FD24993> /Applications/Microsoft Outlook.app/Contents/Frameworks/mso99.framework/Versions/A/mso99

Reason: tried: '/Applications/Microsoft Outlook.app/Contents/Frameworks/mso99.framework/Versions/A/../../../libmbupdx2009.dylib' (code signature in <F40381A1-176B-3C0A-88F9-9016F869C13C> '/Applications/Microsoft Outlook.app/Contents/Frameworks/libmbupdx2009.dylib' not valid for use in process: mapping process and mapped file (non-platform) have different Team IDs), '/Applications/Microsoft Outlook.app/Contents/Frameworks/OutlookCore.framework/Versions/A/../../../libmbupdx2009.dylib' (code signature in <F40381A1-176B-3C0A-88F9-9016F869C13C> '/Applications/Microsoft Outlook.app/Contents/Frameworks/libmbupdx2009.dylib' not valid for use in process: mapping process and mapped file (non-platform) have different Team IDs), '/Applications/Microsoft Outlook.app/Contents/Frameworks/OPF.framework/Versions/A/Resources/../../li

(terminated at launch; ignore backtrace)

Assistance is needed to resolve this issue and update Outlook successfully.

1 answer

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Answer 1

Tammy-Ng 1,970 Microsoft External Staff Moderator

Dear DHANASEKAR NELLAIAPPAN
Welcome to the Microsoft Q&A Forum and thank you for reaching out to share your issue.

Based on the information you provided, I understand that you're experiencing problems using the latest version of Outlook. I'm truly sorry to hear that.

According to my research, you can try the following steps:
-Switch to Legacy Outlook:
If you're currently using the new Outlook interface:

Open Outlook.

Go to the Help menu.

Select Revert to Legacy Outlook.

Restart Outlook and check if the issue persists.

-Uninstall and Reinstall Outlook:
Completely remove Outlook from the /Applications folder.Download the latest stable version from: https://learn.microsoft.com/en-us/officeupdates/update-history-office-for-mac

Reinstall and test again.

-Update via Microsoft Auto Update (MAU):
Open any Office app (e.g., Word).

Go to Help > Check for Updates.

Make sure all Office apps are updated to the latest version.

After updating, consider disabling automatic updates to avoid unexpected version changes that may cause issues.
I hope this information is helpful. Please try the steps above and let me know the result. If you need further assistance, feel free to reach out, I'm always here and ready to support you!

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

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Tammy-Ng 1,970 Reputation points Microsoft External Staff Moderator

2025-07-28T08:08:19.1033333+00:00

Dear DHANASEKAR NELLAIAPPAN

I hope you are well. I am following up regarding the issue you experienced with Outlook for Mac following the recent update to version 1. I would appreciate it if you could let me know whether the matter has been resolved.

Should you require any further assistance or if additional issues have arisen, please feel free to share them. I am fully available and committed to providing support as needed.
DHANASEKAR NELLAIAPPAN 0 Reputation points

2025-07-29T02:32:13.1733333+00:00

I have tried all the steps, but the Issue still persists
Tammy-Ng 1,970 Reputation points Microsoft External Staff Moderator

2025-07-30T13:39:35.9233333+00:00
Dear DHANASEKAR NELLAIAPPAN
Thank you for your responded
Based on the information you've provided, I understand that you're still experiencing difficulties with Outlook crashing, even after attempting all the recommended troubleshooting steps. I'm truly sorry to hear that the issue persists.

As forum moderators, we unfortunately do not have access to detailed diagnostic logs or backend systems due to privacy and security constraints. Because of this, the most effective next step would be to contact Microsoft Support directly for advanced assistance.

Submit a Service Request: The Global Admin should create a service request with Microsoft Support to receive advanced diagnostics and technical assistance. For detailed instructions on how to get support, please refer to: Get support - Microsoft 365 admin | Microsoft Learn

Call Microsoft Support: For additional assistance, find the appropriate contact number at: Customer service phone numbers - Microsoft Support
I hope this information proves helpful.

If my initial answer has been even partially helpful, please consider marking it as “Accepted Answer” so others facing similar issues can find it more easily.

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Outlook for Mac Crashing After Update to Version 16.88.1

1 answer

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