crashes affecting Microsoft Office 365 (both 32-bit and 64-bit versions) when Adobe Acrobat (Pro and Standard) is installed on the machines.

Hello,

We are experiencing a recurring issue affecting Microsoft Word after upgrading Adobe Acrobat and Adobe Reader DC on multiple workstations.

Issue Summary

After performing an upgrade of Adobe Acrobat or Adobe Reader DC, Microsoft Word begins crashing whenever a document is opened in Protected View. Disabling Protected View prevents the crash, but this is not an acceptable workaround due to security requirements.

The only reliable workaround we found is a full reinstallation of both Adobe products AND Microsoft Office.
Repairing Office is not sufficient, and uninstalling Adobe products does not resolve the issue either.

Crash Details (from Windows Event Viewer)

Faulting application name: WINWORD.EXE, version: 16.0.19231.20246, time stamp: 0x690e4192

Faulting module name: ntdll.dll, version: 10.0.22621.6060, time stamp: 0xac55daa3

Exception code: 0xc0000409

Fault offset: 0x00000000000a54f6

Faulting process id: 0x3C88

Faulting application start time: 0x1DC80B37ACC3DBF

Faulting application path: C:\Program Files\Microsoft Office\Root\Office16\WINWORD.EXE

Faulting module path: C:\WINDOWS\SYSTEM32\ntdll.dll

Report Id: ee331c91-fae1-4683-9f72-5ea9a504311d

Observed Behavior

• The crash happens only when opening documents in Protected View.
• Normal opening (when the file is trusted) does not trigger the crash.
• Issue occurs consistently immediately after upgrading Adobe Acrobat/Reader DC.
• Completely reinstalling Adobe + Office temporarily resolves the issue.
• Repairing Office or removing Adobe alone does not fix the problem.

Impact

This issue is currently preventing users from opening documents safely in Protected View, creating a security risk if we disable the feature.

Request

We request assistance from Adobe to:

1. Identify the root cause of this crash related to Word’s Protected View after Adobe product updates.
2. Provide guidance or patches to prevent the crash.
3. Confirm whether a known compatibility issue exists between recent Adobe Acrobat/Reader DC updates and Office 365 builds.
4. Provide recommended remediation steps that avoid disabling Protected View or reinstalling both software suites.

We can provide additional logs, dumps, or reproduce the issue on request if an impacted user is available..

Thanks.