Hi everyone, randomly for about a month now more than 15 of our users are getting a message like this in Outlook while they try to open a folder or an email. 70715-75e3ab97-bbde-451e-8ea3-7f967c20786e.png Closing Outlook works but only for a few minutes. The message comes back everytime. Here is everything I tried : Install Windows 10 20H2 (2004 to 20H2) Updating Office to 2101 (latest version) Recreating the OST file Creating a new profile Reinstalling Office completely Rebuilding the index! Same problem after all this. Putting Outlook in Online mode works since the OST file is not used but we do not want to put this settings to all the users. Are we the only one having this issue ? Thanks

Hi @Kevin Dupont , Are you using Outlook desktop client along with some other programs such as Lync? If yes, please try to exit your Lync completely and restart Outlook to see if the issue has any difference. I found a similar thread about the same issue, the Process Explorer method seems could help many users about this issue, please check if it could be helpful to you: Run Process Explorer and choose "Find Handle or DLL" from the Find menu. Search for '.ost'. This will display all open handles to your Outlook data file. Choose to close all handles to your .ost file Start Outlook again For more information, please check: Outlook fails to open with error: 'Microsoft Outlook' exited without properly closing your Outlook data file . ( Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.) By the way, based on my experience, Disabling hardware acceleration in options/advanced might influence this issue as well, you could try to check this option and restart your Outlook client to see if the issue could be resolved. Outlook 2016: Search locking mail folders. Hope this can be helpful. If an Answer is helpful, please click "Accept Answer" and upvote it. Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Hi @Kevin Dupont , Thanks for your update. As I know, Outlook safe mode also disables other related registry values except for add-ins. So, to confirm if your issue is related to those related registry values, please try the steps below to remove your Outlook completely and see if there is any difference: Exit Outlook and open the Registry Editor Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0 Right-click the Outlook folder Rename it as Outlook1 Restart your Outlook and add your email account to test (Note: Serious problems can occur if you modify the registry incorrectly. Before making changes, back up the registry to restore it in case something goes wrong.) If an Answer is helpful, please click "Accept Answer" and upvote it. Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Well, i can conclude i have the exact same issue. Tried all the same steps, reinstalled office. However i can access my mail using the built in mail in windows 10 and on phones, haven't tried other computers. But if it is like the case above, i would suspect it being a problem with the outlook/office/exchange account.

Try open start and search for feedback and open the Feedback Hub app and report this issue. You may share the link to this post as a reference so Windows engineers would be able to check what steps have you followed so far in your bug report.

I have this problem too, 'Microsoft Outlook' exited without properly closing your Outlook data file. ' OS Name Microsoft Windows 10 Pro Version 10.0.18363 Build 18363 System Model HP ENVY m7 Notebook Processor Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz, 2592 Mhz, 2 Core(s), 4 Logical Processor(s) Installed Physical Memory (RAM) 16.0 GB Model Samsung SSD 850 EVO 500GB OFFICE 365 Version 16.0.13801.20266 PLEASE HELP!

Outlook 365 Windows search exited without properly closing outlook datafile (OST)

Kevin Dupont 51

Hi everyone, randomly for about a month now more than 15 of our users are getting a message like this in Outlook while they try to open a folder or an email.

70715-75e3ab97-bbde-451e-8ea3-7f967c20786e.png

Closing Outlook works but only for a few minutes. The message comes back everytime.

Here is everything I tried :

Install Windows 10 20H2 (2004 to 20H2)
Updating Office to 2101 (latest version)
Recreating the OST file
Creating a new profile
Reinstalling Office completely
Rebuilding the index!

Same problem after all this.

Putting Outlook in Online mode works since the OST file is not used but we do not want to put this settings to all the users.

Are we the only one having this issue ?

Thanks

Reza-Ameri 16,841 Reputation points

2021-02-22T17:22:45.337+00:00

Are they using SSD or HDD hard disk?
Are you seeing any other error?
Are you facing other issues with other applications?
Kevin Dupont 51 Reputation points

2021-02-22T18:36:13.367+00:00

Hi , we have a mix of hard drive.

Some users do have SSD.

The issue happens on both drive type.

There is no other error and all the other apps works fine.

I can dive in the logs to find more info.

Thank you !

14 answers

JeffYang-MSFT 6,241 Reputation points Microsoft Vendor

2021-02-23T02:39:42.567+00:00
Hi @Kevin Dupont ,

Are you using Outlook desktop client along with some other programs such as Lync? If yes, please try to exit your Lync completely and restart Outlook to see if the issue has any difference.

I found a similar thread about the same issue, the Process Explorer method seems could help many users about this issue, please check if it could be helpful to you:

Run Process Explorer and choose "Find Handle or DLL" from the Find menu.

Search for '.ost'. This will display all open handles to your Outlook data file.

Choose to close all handles to your .ost file

Start Outlook again

For more information, please check: Outlook fails to open with error: 'Microsoft Outlook' exited without properly closing your Outlook data file. (Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.)

By the way, based on my experience, Disabling hardware acceleration in options/advanced might influence this issue as well, you could try to check this option and restart your Outlook client to see if the issue could be resolved. Outlook 2016: Search locking mail folders.

Hope this can be helpful.

If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
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1 person found this answer helpful.
JeffYang-MSFT 6,241 Reputation points Microsoft Vendor

2021-02-24T07:41:13.697+00:00

Hi @Kevin Dupont ,
Just checking in to see if above information was helpful. If you have any further updates on this issue, please feel free to post back.

Kevin Dupont 51 Reputation points

2021-02-25T20:47:39.487+00:00

Hi, we are not using Lync (Skype for busines).

It is installed on the computers because of O365 but people are not using it.

It is not running also when I look in the process.

I tried running the process explorer but wierdly, it does not show the .ost handle.

I tried to search .exe for exemple and it shows the list.

.ost makes the program search for ever so I can't see all the program that have a hand on it.

Thanks

JeffYang-MSFT 6,241 Reputation points Microsoft Vendor

2021-03-01T08:58:40.547+00:00

Hi @Kevin Dupont ,

Thanks for your update. Sorry to hear that those methods above could not work.

I am using Outlook 365(Current Channel) recently, but seems have not encountered the same issue yet. So, what's the version of these problematic Outlook clients? (File > Office Account > About Outlook). Please make sure you have upgraded your Outlook to the latest version.

According to my search, Outlook add-ins may also keep occupying the .ost file and cause similar errors. So, it is suggested to start your Outlook in safe mode (Press Win + R, type “outlook /safe”, press Enter.) and see if the issue continues.

By the way, since the issue is related to local .ost files and the search feature. As a workaround for Exchange cache mode, please try to uncheck the OST file type via Index Options > Advanced > File Types and restart your windows to see if the error can be temporarily stopped.

Any update, please feel free to post back.

JeffYang-MSFT 6,241 Reputation points Microsoft Vendor

2021-03-05T10:10:21.657+00:00

Hi @Kevin Dupont ,
It has been a while, how is everything going?
If you have any update about this issue, please feel free to post back.

Kevin Dupont 51 Reputation points

2021-03-05T13:16:18.81+00:00

Hi, we are on the current channel (same as yours) so we are running the latest version.

Starting Outlook in safe mode seems to work. I checked the addon and we have all the same. Some users have this issues some others don't.. It could be SBU addon but we can't remove it since Skype for business is integrated inside office 365.

Removing the OST works but users need to be able to do some search so its not really a solution.

Thank you very much !

JeffYang-MSFT 6,241 Reputation points Microsoft Vendor

2021-03-09T06:16:49.343+00:00

Hi @Kevin Dupont ,
Thanks for your update.
It is no need for us to remove the Skype for business. It could be easy to confirm to if the issue is related to the SBU add-in. You could try to temporarily disable the SBU add-in(Outlook > File > Options > Add-ins > Manage > Go > Uncheck Skype add-ins) on the device in question and see if the issue could be resolved.

Kevin Dupont 51 Reputation points

2021-03-10T16:24:07.603+00:00

I did try to turn it off but the issue is still there.

I tried turning off all the addon we do not use and same thing happen.

In safe mode it does not do it, really wierd.

Thanks
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JeffYang-MSFT 6,241 Reputation points Microsoft Vendor

2021-03-12T08:34:49.623+00:00
Hi @Kevin Dupont ,

Thanks for your update.

As I know, Outlook safe mode also disables other related registry values except for add-ins. So, to confirm if your issue is related to those related registry values, please try the steps below to remove your Outlook completely and see if there is any difference:

Exit Outlook and open the Registry Editor

Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0

Right-click the Outlook folder

Rename it as Outlook1

Restart your Outlook and add your email account to test

(Note: Serious problems can occur if you modify the registry incorrectly. Before making changes, back up the registry to restore it in case something goes wrong.)

If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Please sign in to rate this answer.
Kevin Dupont 51 Reputation points

2021-03-12T19:56:55.277+00:00

I tried that and the issue is there.

It makes the same things even if I create a new profile (outlook profile or Windows profile).

There is no apps running that could have a handle on the OST file, I dont know why safe mode works and not regular mode.

Thank you
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Jonas Haudrup Aamann Jessen 16 Reputation points

2021-03-17T09:06:04.773+00:00

Well, i can conclude i have the exact same issue.
Tried all the same steps, reinstalled office.
However i can access my mail using the built in mail in windows 10 and on phones, haven't tried other computers.
But if it is like the case above, i would suspect it being a problem with the outlook/office/exchange account.
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Kevin Dupont 51 Reputation points

2021-03-17T12:24:55.24+00:00

These accounts works for us too inside the mail app and on their phone.

IIts just Outlook and some users, not all of them.

The issue happend at the same time for everyone, this makes it even more wierd.

Thanks

Jonas Haudrup Aamann Jessen 16 Reputation points

2021-03-17T13:28:52.593+00:00

I remember it just starting one day, which i assume is the same case for you.
I don't know what you are using, but i'm using office365 with exchange online. So i would assume that this is an issue MS have?

Kevin Dupont 51 Reputation points

2021-03-17T16:08:38.91+00:00

yeah seems to be the same.

We have Office 365 with an onprem 2013 Exchange.

I have been researching for hours and nothing works.

Thanks

JeffYang-MSFT 6,241 Reputation points Microsoft Vendor

2021-03-18T07:15:14.743+00:00

Hi all,
Thanks for all your updates here.

I am still researching about this issue as well. Though have not found much more useful information yet. I tried to search from Outlook known issue list, but also failed to find any similar ones yet.

Are you both using the same Outlook version here? Or have the same issue in different versions of Outlook? Can the safe mode method also works for @JonasHaudrupAamannJessen-2515 's issue?

I would keep trying to do more related research, and if I got any updates, I will post back here as soon as possible. Thanks for your patience and understanding.

Jonas Haudrup Aamann Jessen 16 Reputation points

2021-03-19T12:57:09.077+00:00

Safe mode, works.
But as we all know, that is not a reliable solution and certainly not something that would be sufficient in a production enviroment.
I

Above is 2 tasks in my task manager that shows when running outlook.

Version is shown in the image above.

And i also noticed some events in the event viewer for applications.
Which i also have attached in XML format.
79664-events.xml

Mik Gotier 1 Reputation point

2021-04-28T18:11:37.613+00:00

We have the exact same issue with one of my user (Outlook 365, Windows 10, Exchange online mail account).
Work fine with the safe mode.
Work fine if we don't use the cache Exchange mode.
Work fine for few minutes if we close than reopen Outlook. The issue reappear maybe 4-5 minutes after.
We tried everything proposed here by the others but nothing works for us.

Thanks
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Reza-Ameri 16,841 Reputation points

2021-03-19T16:24:51.42+00:00

Try open start and search for feedback and open the Feedback Hub app and report this issue.
You may share the link to this post as a reference so Windows engineers would be able to check what steps have you followed so far in your bug report.
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Cesar Hernandez 1 Reputation point

2021-03-19T23:37:18.383+00:00

I have this problem too, 'Microsoft Outlook' exited without properly closing your Outlook data file. '
OS Name Microsoft Windows 10 Pro
Version 10.0.18363 Build 18363
System Model HP ENVY m7 Notebook
Processor Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz, 2592 Mhz, 2 Core(s), 4 Logical Processor(s)
Installed Physical Memory (RAM) 16.0 GB
Model Samsung SSD 850 EVO 500GB
OFFICE 365 Version 16.0.13801.20266

PLEASE HELP!
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