Outlooks keep crashing

we see the same behaviour on machines with the latest Outlook Build 20026.20182 on Windows 11
the machines with Build 20026.20166 are working fine.

Safe-Mode did not help
New Oulook-Profile does not help
Disabing the spell checking (the wriggly red lines on typos) did not help

Same issue here, started today 30/06/2026. Outlook (not "new Outlook") Win 11 V 2605 build 20026.20182

To clarify, outlook is crashing on command as soon as I right click the message body. There doesn't need to be a spelling error, there doesn't even need to be any text. I can boot, open outlook, start a new email, right click on the message body, and it crashes to desktop. It also crashes when pressing the context menu key on the keyboard. So obviously it's Outlook's context menu that is crashing Outlook.

Right clicking on the subject line, the address fields, navigation pane, folders etc are fine, it's just the message body that crashes it.

I have the same problem. Started yesterday. I am using Outlook classic.

Same issue for us Build 20026.20168. New profile, same issue. Safe mode, same issue. Only some users affected. WIth problem users, every time they right click, outlook crashes. Event viewer shows:

Faulting application name: OUTLOOK.EXE, version: 16.0.20026.20168, time stamp: 0x6a23f14f

Faulting module name: mso.dll, version: 0.0.0.0, time stamp: 0x6a23ee6b

Exception code: 0xc0000005

Fault offset: 0x00000000000f349c

Faulting process id: 0x7c84

Faulting application start time: 0x01dd08603807bdaa

Faulting application path: C:\Program Files\Microsoft Office\root\Office16\OUTLOOK.EXE

Faulting module path: C:\Program Files\Common Files\Microsoft Shared\Office16\mso.dll

Report Id: bdb2e8cd-4cb8-4e9c-8ab9-09d65ca06a98

Faulting package full name:

Faulting package-relative application ID:

TENTATIVE UPDATE:

Rebooted twice, issue persists.

Rebooted a third time, issue appears to be resolved. No additional debugging, just a simple reboot (thrice).

I will monitor and update if issue returns.

Additional edit - it appears that the third reboot prompted outlook to update to 20131.20090, which other users are reporting is a bug fix for exactly this.

Have you tried restarting the machine @Paul ? Some users have reported that it may take 2 - 3 reboots to fully resolve the issue. You might also want to consider updating to the latest version (20090). https://learn.microsoft.com/en-us/officeupdates/update-history-microsoft365-apps-by-date#version-history

Updating outlook to 2606, Build: 20131.20090 fixes this issue for us.

I haven't rebooted, we are using Citrix and these effectively reimage when rebooted. Just trying Outlook 2606 Build: 20131.20090...Fingers crossed

Run Online Repair, it updates to 2606 (20131.20090).

Fixes it in 10 minutes

Run an Online Repair, will update to 2606(20131.20090)

Takes 10-15 minutes and works first time

Use Online Update in any of the Office Applications to update to
Version 2606 (Build 20131.20090)

Tested on 3 users with the version 2606 Build: 20131.20090. Issue now resolved for them! thanks @RossCrooks-7034 and @Anonymous !

Hello.

We are experiencing the same issue on our side.

While writing messages, the window has already closed several times today, and Outlook has also crashed occasionally. We have now updated with the latest patches.

We hope the issue has been resolved.

Running 365 online repair also works

All my clients are up to date, outlook still having those issues currently its up to 124 Windows 11 computers, 6 MACs and 12 Windows 10 machines.

This is all linked with office 365.

Have you created ticket in Admin center to report this to Microsoft @Alex Tovey

Aside from updating, you could also try rolling back Outlook to version 20168- Open an elevated Command Prompt (search for Command Prompt, right‑click, and choose Run as administrator).

• Run the following command: "%programfiles%\Common Files\Microsoft Shared\ClickToRun\officec2rclient.exe" /update user updatetoversion=16.0.20026.20168

For macOS, could you also share the Outlook version where the issue occurs, along with the macOS version?

From what I can see, the latest Outlook for Mac version is June 23, 2026 - 16.110.1 (26062112), so it would be helpful to confirm whether you’re on this version or an earlier one.

@Alex Tovey @Anonymous I submitted a bug for this issue this morning. The Outlook Escalation Engineers debugged it and found that it was already tracked as fixed by a Word bug. The fix is in Current Channel 20103.00000 and fixed in Monthly Enterprise Channel in builds 20131.00000 and 20228.00000. I will have to check further if this somehow got into Mac Outlook. If you update clients to the latest build per respective channel, are you still seeing the issue? You can see the latest updates on Update History, https://learn.microsoft.com/en-us/officeupdates/update-history-microsoft365-apps-by-date?.

Hello @Anonymous thank you so much for the quick update and for your support on this, really appreciate you jumping on it so fast. And sorry for the ping earlier as well.

Hopefully the fix rolls out broadly soon and helps resolve the issue for everyone still affected. I’ll also continue to monitor from my side and check whether users are still seeing the same behavior after updating to the latest builds.

thanks for the heads up on this. Just to make sure, the fixed builds are already out for this issue. Any customer currently hitting this issue can address it by updating to the latest build on the respective channels. If you find that is not true anywhere, please let me know.

To update your Outlook build, click File, Office Account, Update Options, Update Now.

Yes, mine is doing the same thing!

Hi Team,

We are continuing to experience issues with the New Outlook. Several users within our company have reported the same problem, and some of our customers are experiencing it as well.

We have also tested on a freshly provisioned laptop, but the issue persists.

When users click on emails or any other options within Outlook, the application becomes unresponsive and no action is performed.

Could you please investigate this issue and advise on the next steps?

Thank you.

Hi @Vignesh Vivekanandhan since the issue is affecting several users in your company and even some customers, at this point I think it would be best to collect the Outlook version and Windows version from all affected machines, then open a support ticket with Microsoft Support as soon as possible so they can investigate this from the backend side.Before doing that, I would still suggest making sure the affected devices have already been updated to the latest available version. Microsoft released Version 2606 (Build 20131.20112) on June 30, which includes fixes for this issue. If the affected users are not on this build yet, please update Outlook/Microsoft 365 Apps first and test again.

https://learn.microsoft.com/en-us/officeupdates/update-history-microsoft365-apps-by-date?#version-history

If the issue still happens after updating, please also check whether the affected users are using the 32-bit version of Office/Outlook. Some users have reported that the issue affected the 32-bit version, and moving to the 64-bit version, then updating to the latest build, resolved the problem for them.

In addition, one user in this thread, Eric, mentioned that deleting the following registry key helped in their case: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\ExperimentConfigs

You may want to test this on one affected machine first before applying it more broadly.

Read online this issue is affecting thousands of people who have had an update, how long is this going to take Microsoft to resolve as this is causing massive issues for everyone, not just us.

Microsoft please update us all when this issue will be resolved.

Hi @Anonymous

thanks, we have tried the same still no luck. when user tried open the email, or click settings nothing happens.

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\ExperimentConfigs this is not available for the machine

Hello @JK

First, I'm sorry for the inconvenience this issue has caused. I completely understand the impact, especially when it affects daily work across multiple users.

From what I've seen, Microsoft became aware of the issue and began investigating it shortly after reports started coming in. It also appears that a fix has already begun rolling out, with some users reporting improvement after updating to the latest available build.

If you're still experiencing the problem, please make sure you're running the most recent version available to your update channel and let me know whether the crashes continue after updating.

Microsoft is still actively investigating the issue and working toward a broader official resolution for any users who remain affected. Unfortunately, as this is a public user-to-user forum, I don't have access to internal timelines or the ability to provide ETA information.

Again, I apologize for the disruption this has caused. If Microsoft releases any significant updates, I'll post them in this thread as soon as they become available.

Thank you for your patience and understanding.

Well @Vignesh Vivekanandhan to be honest, at this point, I'm not sure what else I can realistically suggest from the forum side.How is your support ticket progressing? Microsoft is still actively investigating this issue, so there is currently no confirmed resolution or additional workaround that I can recommend.

Stupid thing is we did not do any Office or Outlook update, all we did was a Windows Update ands that must have included updating Outlook and has caused the crash, when I go to Outlook it says no updates available.

From what I've seen, this does not appear to be caused solely by an Outlook update. You may want to refer to Gabe's response (Microsoft employee) for additional details and context regarding the ongoing investigation.

Also, when you say Outlook reports "no updates available," could you share your exact Outlook version and build number @JK ?

Outlook 365 build number 20131.20090

If you're already on build 20090, you might want to try a few more restarts and see if the issue resolves itself @JK . I've seen reports from some users that after running an Office Repair, the newer update became available, or that the issue was resolved after a couple of reboots once the latest build had been installed.

If that doesn't help, I'd recommend opening a support ticket with Microsoft so they can investigate your specific case further. Unfortunately, there isn't much more we can do from the forum side while Microsoft is still actively investigating the issue.

We have done this many times and it still does not work, a friend has outlook 2016 and called me and asked if we had the same issue so it appears this is not a office 365 issue as they are on a 10 year old outlook 2016 build and have the same issue.

This seems to now be acknowledged by Microsoft. https://admin.cloud.microsoft/?#/servicehealth/:/alerts/EX1409958

I am having the same issues right clicking. I can’t cut and paste from other documents into an email. It’s quite a pain in the ass and I have seen a fix come out yet.

We are continuing to experience issues with the New Outlook.

@Vignesh Vivekanandhan

Most people reporting this seem to be running the classic Outlook. If you are seeing a problem in the new Outlook, maybe you should start a new thread, to get more attention for your question.

See also the support overview at https://support.microsoft.com/en-US/Support/known-issues/fixes-or-workarounds-for-recent-issues-in-new-outlook-for-windows .

Same problem here. And after applying Windows updates to a user machine with this symptom, Outlook will not load.

Thanks, Microsoft. Is there a chart available that shows the negative effects of Microsoft security updates?

Seems like each update introduces a bug that is fixed in a later update. Microsoft updates = more Helpdesk tickets.

Hello @Todd Nichols how is this issue progressing on your side?

I recently received information that Microsoft has released a fix today which appears to improve this issue. Could you please recheck?