After installing Windows Update KB5094126 (June 2026) , our application fails when opening Word via COM automation. Error: HRESULT 0x80020005 (DISP_E_TYPEMISMATCH) Type mismatch Happens during Documents.Open() (IDispatch call) Fully reproducible Works again after uninstalling KB5094126 Impact: Breaks Word integration / reporting completely Affects multiple environments Tested with: Word 2013 Word 2021 Microsoft 365 → So not Office-specific, likely COM/Windows layer Question: Has anyone seen this after KB5094126? Was there a change in COM/OLE automation or VARIANT handling in this update?

Hello everyone, Thank you for the additional details and confirmation regarding this issue. It appears this issue is affecting multiple users after installing KB5094126. Given this, I strongly recommend contacting your organization’s IT administrator and asking them to report the issue through the Microsoft Admin Center. This helps Microsoft track, prioritize, and investigate service-related issues more effectively. Steps for the Microsoft 365 Admin: Sign in to the Microsoft 365 Admin Center . Go to Health > Select Service health. Click Report an issue. Appreciate your patience and understanding. Warm thanks.

We have the following issue, when automating Word via VB/VBVA and the KB is installed. The fields that we fill are all empty, but there is no error thrown. The issue occurs only when using Word 64-bit. Using the 32-bit version everything seems to work as expected.

one problem remains Word is not closing ! @Justin

Nearly 500 customers have the problem , all Word Version with Remote COM ! .Open has definitiv a problem ! Your software stack is doing this, after deinstalling KB5094127 the problem was gone ! Get on your seats and repair it, very sad because of our customers are very sad ! Microsoft sucks ! C++

After installation of KB5094126 the Word integration over COM fails

Daratha, Paul 95

After installing Windows Update KB5094126 (June 2026), our application fails when opening Word via COM automation.

Error:

HRESULT 0x80020005 (DISP_E_TYPEMISMATCH)
Type mismatch

Happens during Documents.Open() (IDispatch call)
Fully reproducible
Works again after uninstalling KB5094126

Impact:

Breaks Word integration / reporting completely
Affects multiple environments

Tested with:

Word 2013
Word 2021
Microsoft 365

→ So not Office-specific, likely COM/Windows layer

Question: Has anyone seen this after KB5094126? Was there a change in COM/OLE automation or VARIANT handling in this update?

Daratha, Paul 95 Reputation points

2026-06-11T19:00:40.4933333+00:00
Other sources complains about same problem. See

https://www.reddit.com/r/sysadmin/comments/1u31bje/kb5094126_breaking_word_integration_with_some/?rdt=38900

https://forums.zotero.org/discussion/132111/word-for-windows-zotero-experienced-an-error-updating-your-document
Viorel 127.3K Reputation points

2026-06-11T19:05:54.51+00:00

Which code has to be changed?
Leigh Menzel 10 Reputation points

2026-06-11T21:19:51.19+00:00

Yes, we are having the exact same issue with our software. I am looking for a solution now but was thinking I might update our Word and Excel reporting to a later version. You mentioning that it is also happening with Word 2021 and Office 365 is a huge help, thanks. I won't bother with that step for now then.
Lahinirina, Eric 15 Reputation points

2026-06-12T10:15:01.58+00:00

We are having the exact same issues. We are using Word COM automation with C++/MFC. And what we see so far is that calling a Word object method through a COleDispatchDriver inherited class crashes if you provide an optionnal parameter with COleVariant vtMissing((long)DISP_E_PARAMNOTFOUND, VT_ERROR);

This issue is quicky affecting all of our customers worldwide.
Leandro Rodrigues 5 Reputation points

2026-06-12T14:54:25.5366667+00:00

I've had the same issue with the OLE automation, solved after the hotfix removal.
Alan Reagan 16 Reputation points

2026-06-12T17:18:32.7333333+00:00

A vendor with affected software is attributing it to changes to Virtualization‑Based Security (VBS), Hypervisor‑Enforced Code Integrity (HVCI), and updated code integrity baselines. KB5094126 covers critical vulnerabilities. This needs to be fixed with Known Issue Rollback so KB5094126 doesn't have to be removed.
Koby Roberts 0 Reputation points

2026-06-16T01:02:30.42+00:00

I was able to use the Open method. However, I had to go straight IDispatch. I have to go around the MFC Wrappers.
Justin 30 Reputation points

2026-06-16T14:43:17.18+00:00

@Jürgen Hillmann

Nice to hear!!

I'm from Germany... ;-)
Jürgen Hillmann 5 Reputation points

2026-06-16T14:45:37.0266667+00:00

oh cool , i am also from Germany -

die Deutschen sind doch nicht so schlecht ! :-)
Jürgen Hillmann 5 Reputation points

2026-06-16T14:46:28.0666667+00:00

@Justin hope MS is not changing this behaviour anymore !!!!!
Houmard Matthias 0 Reputation points

2026-06-17T07:54:08.12+00:00

Following the installation of KB5094126, not only was the data transfer process in Word blocked, but the OLE or COM data transfer process in Excel was also blocked by third-party software. Interestingly, in Excel, the table was created in each instance, the header rows were visible and correct, but the table was not populated with content.
ChuckieAJ 411 Reputation points

2026-06-24T16:40:08.1666667+00:00

I am experiencing this now too with Word automation, including my userbase.
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Answer accepted by question author

Homero Junior 80

My integration had been having issues ever since the update that broke it. All it took was installing this update—KB5101650—and everything started working again. Just install update KB5101650, restart, and you're all set.

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11 additional answers

Hin-V 16,830 Reputation points Microsoft External Staff Moderator

2026-06-12T16:29:45.8533333+00:00

Hello everyone,
Thank you for the additional details and confirmation regarding this issue.

It appears this issue is affecting multiple users after installing KB5094126. Given this, I strongly recommend contacting your organization’s IT administrator and asking them to report the issue through the Microsoft Admin Center. This helps Microsoft track, prioritize, and investigate service-related issues more effectively.

Steps for the Microsoft 365 Admin:

Sign in to the Microsoft 365 Admin Center.

Go to Health > Select Service health.

Click Report an issue.

Appreciate your patience and understanding.

Warm thanks.
Was this answer helpful?

3 people found this answer helpful.
ChuckieAJ 411 Reputation points

2026-06-24T16:40:38.08+00:00

I only have a personal account so can't go down this route.
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Benny Bürger 0 Reputation points

2026-06-22T14:23:59.0533333+00:00

We have the following issue, when automating Word via VB/VBVA and the KB is installed.

The fields that we fill are all empty, but there is no error thrown.

The issue occurs only when using Word 64-bit.

Using the 32-bit version everything seems to work as expected.
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1 person found this answer helpful.

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Jürgen Hillmann 5 Reputation points

2026-06-16T12:33:05.7066667+00:00

one problem remains Word is not closing ! @Justin
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Justin 30 Reputation points

2026-06-16T13:58:13.2166667+00:00

@Jürgen Hillmann

Strange, I don't have this problem. Are you sure you are not missing the _Application::Quit command?

Does the Word window stay open or is it just the process remaing in the task manager process list?

Jürgen Hillmann 5 Reputation points

2026-06-16T14:08:21.65+00:00

a i understand

.Quit one ist for Documents, this only does ist for Document/s : Capplication there is also a Quit zhis one then is closing it !

Wow you are a genius ! Thanks ! this is solving our problem !

Koby Roberts 0 Reputation points

2026-06-16T14:21:12.6166667+00:00

HRESULT hr = InvokeMethod(g_wordApp, OLESTR("Quit"), args, 3, nullptr); if (FAILED(hr)) { error = -2; PrintComFailure(L"Word.Application.Quit", hr); }

Does not stop the actual WinWord process until my calling app closes.

Justin 30 Reputation points

2026-06-16T14:27:26.26+00:00

@Jürgen Hillmann

It sounds to me that you're missing _Documents::Close or _Application::Quit call since all of the 3 commands use the same DISPID 0x451.

Please make sure to close word like this:

_Document::Close(...)

_Document::ReleaseDispatch()

_Documents::Close(...)

_Documents::ReleaseDispatch()

_Application::Quit(...)

_Application:::ReleaseDispatch()

In your example:

oDoc.Close(...)

oDoc.ReleaseDispatch()

oDocs.Close(...)

oDocs.ReleaseDispatch()

oWord.Quit(...)

oWord.ReleaseDispatch()

Jürgen Hillmann 5 Reputation points

2026-06-16T14:29:45.4333333+00:00

Right ! this is great solution now it works ! great job !

where are you from ?

Koby Roberts 0 Reputation points

2026-06-16T15:29:33.3933333+00:00

That worked for me as well. Thx!
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Jürgen Hillmann 5 Reputation points

2026-06-12T06:32:45.7866667+00:00

Nearly 500 customers have the problem , all Word Version with Remote COM ! .Open has definitiv a problem ! Your software stack is doing this, after deinstalling KB5094127 the problem was gone !

Get on your seats and repair it, very sad because of our customers are very sad !

Microsoft sucks ! C++
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1 person found this answer helpful.

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After installation of KB5094126 the Word integration over COM fails

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