Fix: “The Ordinal 9104 Could Not Be Located” in Microsoft Office

An accounting team member at one of our customers reported that Word, Excel and Outlook had stopped opening on her workstation. Documents stored in OneDrive would only open with the View Online option, while the desktop apps threw a series of DLL errors. The user had already tried restarting and could open files in the browser, but the desktop suite was unusable. Here is what we found and how to fix it.

Symptoms

When opening Microsoft Word from a OneDrive folder, users see:

WINWORD.EXE – Ordinal Not Found
The ordinal 9104 could not be located in the dynamic link library C:\Program Files (x86)\Microsoft Office\Root\Office16\wwlib.dll.

Excel throws a separate prompt suggesting safe mode after a failed launch:

Excel couldn’t start last time. Safe mode could help you troubleshoot the problem, but some features might not be available in this mode. Do you want to start in safe mode?

Outlook surfaces a similar dialog referencing MSO.dll:

Variations of the error reference different ordinal numbers (4051, 5380, 9104) and DLL names (wwlib.dll, mso.dll, mso20win32client.dll), but the underlying cause is the same. Files can be opened in the browser via View Online, only the desktop apps fail.

Affected Software

• Application: Microsoft 365 Apps (Word, Excel, Outlook, PowerPoint)
• Platform: Windows 10 and Windows 11
• Related Services: OneDrive for Business, SharePoint Online

Cause

The ordinal error appears when one or more Office DLL files are out of sync with the Office executable that loaded them. This usually happens after a failed or partial Office update, a Windows update that interrupted an Office click-to-run process, or co-existing Office installations (for example Microsoft 365 Apps installed alongside a leftover Office 365 for Business or volume-licensed copy). The .exe expects a specific function index inside wwlib.dll or mso.dll that the on-disk version no longer exports, which is why Office throws an “ordinal not found” message rather than a generic crash.

Resolution

An online repair of Microsoft 365 Apps re-downloads every Office binary and resets DLL versions to a matched set. This resolves the issue in the vast majority of cases.

1. Close all Office applications, including Outlook and any Teams meeting that has the Outlook add-in loaded.
2. Open Settings > Apps > Installed apps (Windows 11) or Settings > Apps > Apps & features (Windows 10).
3. Find Microsoft 365 Apps for enterprise (or your installed Office edition), click the three dots, then choose Modify.
4. Select Online Repair (not Quick Repair), then click Repair. The process downloads the full Office package and takes 10 to 20 minutes depending on connection speed.
5. When the repair completes, restart Windows. Open Word, Excel and Outlook from the Start menu to verify the apps launch without the ordinal error.
6. If a second Office installation is present (for example an older Office 365 for Business or Office 2016 Standard), uninstall the redundant copy from Installed apps before running the online repair again.

Quick Repair will not fix this error because it does not replace the affected DLLs, only the registry and shortcut state. The online repair is required.

Important Notes

• If multiple users on the same device hit the same error, the issue is at the machine level. The online repair only needs to run once.
• If the error returns after the next Office update, check Group Policy and Microsoft 365 Apps admin centre for stuck or conflicting update channels (for example Monthly Enterprise vs. Current Channel).
• For Remote Desktop Session Host or AVD environments, the online repair must be performed in install mode (change user /install) and users should be logged off during the repair.

Related Resources

• Fix: Microsoft Teams Meeting Add-in Causing Outlook to Crash
• Fix: Application Errors on Windows Server (Corrupted RDS Profile)
• Fix: Error Opening PDF Attachments in Outlook
• Microsoft Support: Repair an Office application
• Microsoft Learn: Troubleshoot Microsoft 365 Apps installation issues

If you need help resolving Microsoft Office DLL or ordinal errors across your business, get in touch with our team.