Word Files Not Opening from Network Drives (Microsoft® Word for Microsoft 365 MSO Version 2601 Build 16.0.19628.20166)

Question

Good day,

I'm encountering a problem across my organization where Microsoft Word crashes whenever a user tries to open a .docx file stored on a network drive (on‑premises server). After the crash, Word displays the following prompt:

"Word 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?"

What I've observed so far:

• The issue occurs only with Microsoft 365 (MSO) Version 2601, Build 16.0.19628.20166
• Rolling back to Version 2512 eliminates the problem
• As a temporary workaround, launching Word first from the Start menu and then opening the network‑drive file prevents the crash.

Has anyone else experienced this behavior with the same build? Is this a known issue for Microsoft 365 Version 2601, Build 16.0.19628.20166? Any insights or suggested fixes would be greatly appreciated.

Answer 1

This is a user-to-user support forum.

Microsoft is not hearing about your problems from what you post here. You are discussing a problem with your fellow users here. We can give good advice about how to work with Word as it is and give suggestions for making it work properly.

Designers and their supervisors do see feedback. (You will almost certainly not get a direct response to that feedback but they do see it.)

Here is more about that:

https://answers.microsoft.com/en-us/msoffice/forum/all/giving-feedback-on-microsoft-word-or-other/8df81a9b-84aa-46ef-bf88-24fb7fec96ba

I suggest using the public feedback portal so other users can see your feedback, comment and vote. If you want, you can post the URL of your feedback with your question here to lead others with the same problem to your feedback. Be the “squeaky wheel” that gets fixed!

Answer 2

Bonjour,

Nous rencontrons le même problème dans notre organisation, reproductible sur 2 postes Windows utilisant Microsoft 365 Apps (32 bits) avec ouverture de documents Word depuis un NAS QNAP via SMB (lecteur réseau mappé)

Symptômes

• Double-clic sur un .docx / .doc situé sur le lecteur réseau :
  • le splash Word apparaît puis Word se ferme / aucun document ne s’ouvre.
  Le même fichier, copié en local (Bureau) s’ouvre sans problème. Ouvrir le fichier via Word > Fichier > Ouvrir fonctionne. Clic droit > Ouvrir avec > Word fonctionne. Les fichiers Excel et autres types (images, etc.) ne sont pas impactés.

Reproduction

1. Monter un partage SMB en lecteur réseau.

Double-clic sur un .docx présent sur le lecteur réseau.

Word crash/exit immédiat.

Logs / Observateur d’événements

Event Viewer > Windows Logs > Application

Event ID 1000 – Application Error

Application : WINWORD.EXE 16.0.19628.20166

Module fautif : ucrtbase.dll 10.0.19041.3636

Exception : 0xC0000005

Fault offset : 0x0004F0D4

Chemins :

C:\Program Files (x86)\Microsoft Office\Root\Office16\WINWORD.EXE

  `C:\Windows\System32\ucrtbase.dll`
  

Versions testées

• Microsoft 365 Apps : Version 2601 (build 16.0.19628.20166) → ne fonctionne pas
• Mise à jour testée : Version 2601 (build 16.0.19628.20204) – 10 Feb 2026 → ne fonctionne pas (toujours reproductible)

Contournements

• Clic droit > Ouvrir avec > Word : fonctionne
• Ouvrir Word puis Fichier > Ouvrir : fonctionne

Solution stable identifiée

Rollback vers Version 2512 (build 16.0.19530.20184) :

"%programfiles%\Common Files\Microsoft Shared\ClickToRun\officec2rclient.exe" /update user updatetoversion=16.0.19530.20184

À noter : désactiver temporairement les mises à jour Office (Fichier > Compte > Options de mise à jour) pour éviter le retour automatique sur une build impactée.

Si vous avez une référence officielle (KB / Known Issue) ou une build corrigée (Current Channel / Monthly Enterprise) permettant une résolution durable sans rollback, je suis preneur.

Cordialement

Answer 3

Hi @Luke Wildeman,

Thank you for reaching out to the Microsoft Q&A forum. Based on the details you shared, this behavior appears to be related to Microsoft Word for Microsoft 365 Version 2601 (Build 16.0.19628.20166). The issue has been observed when users open .docx files directly from a network drive (on-premises file server) by double-clicking the file. In this scenario, Word may crash during startup and subsequently prompt to open in Safe Mode. I have confirmed the following:

• The issue occurs only on Version 2601 (Build 16.0.19628.20166).
• Rolling back to an earlier version (for example, Version 2512) resolves the issue.
• As a temporary workaround, opening Word first from the Start menu and then opening the file from within Word prevents the crash.
• At this time, the issue is not documented as a known issue in the official Current Channel or Current Channel (Preview) release notes.

This strongly suggests a regression issue in this specific build, potentially related to how Word initializes when opening files from network locations. I recommend trying the following steps in order:
1. Disable Word add-ins (for testing)

• Open Word → File → Options → Add-ins
• Manage: COM Add-ins → Go
• Disable all add-ins, then restart Word
• Test opening a document directly from the network drive (If this resolves the issue, add-ins can be re-enabled one by one to identify the cause.)

2. Add the network location to Trusted Locations

• Word → Options → Trust Center → Trust Center Settings
• Trusted Locations → Add new location
• Add the network path (UNC or mapped drive) and allow subfolders

3. Temporarily test Protected View settings

• Word → Options → Trust Center → Trust Center Settings → Protected View
• Temporarily disable Protected View options and test again (This is for troubleshooting only and not recommended as a permanent configuration.)

4. Test UNC path versus mapped drive

If the file is currently opened from a mapped drive (for example, Z:), please test opening the same file using the UNC path (\ServerName\Share\File.docx).

5. Temporary mitigation

• Continue using one of the following until a permanent fix is available:
• Open Word first, then open the document from within the application
• Remain on a previous stable version (such as Version 2512)

If the issue continues after these steps, the next recommended action would be to engage Microsoft Support so that a technical support engineer can review crash logs, verify backend behavior, and escalate the case if required.
How to Submit the Support Ticket in Admin Center: Get support - Microsoft 365 admin | Microsoft Learn 

Please let me know the results after testing the above steps, or if you have any questions or concerns. I will be happy to assist further.

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