Multiple users experiencing Outlook 365 freezes/white screen

Question

Multiple users experiencing Outlook 365 freezes/white screen

Scott Gray 96

We have multiple Outlook 365 users experiencing freezes/white screen from 10 seconds to 5 minutes or more when using a large shared user mailbox. Users are configured with personal user mailbox and secondary user mailbox (50Gb in size) which is not cached. In Place backup is enabled for the second mailbox. Second user/mailbox is assigned E3 licence. This specific team uses the secondary mailbox to triage and manage many incoming emails with attachments and they need to coordinate with each other and move mail items into sub folders based on region or job type. The mailbox is in online only mode because caching not only requires a huge OST and takes a long time to download on new installs but also results in delays between users when items are moved, flagged or categorised.

I have tried the following none of which has made a difference to performance with users :

Creating a new Outlook profile
Running Outlook in Safe mode to eliminate plugins
Disabled web plugins when outside of Safe mode
Disabling Anti-virus (Webroot SecureAnywhere)
Enabling cached mode for the secondary mailbox and setting retention to 3 months
Applying all windows updates and Office 365 updates
Running continuous ping in PingPlotter to determine any connectivity issues (none identified)
Disabling graphics hardware acceleration
Disabling “Optional connected experiences”
Running SARA/Outlook diagnostic tool – Nothing obvious or critical identified from what I can see
Checking AutoDiscovery settings - Nothing obvious or critical identified from what I can see
Contacting Outlook support via Outlook Help menu (zero luck there)
Checking Outlook connection status (control right click on Outlook icon > Connection status) for errors (none) and reconnecting when locked up - No effect, doesn't brink Outlook back
Tweaking NIC settings to disable low power mode etc

The only suggestions from Outlook support were that users should be using a shared mailbox instead of a user mailbox but I cant see how this would make any difference at all to connectivity to ExO. They recommend caching user mailboxes and un-caching shared mailboxes or at the least disabling download of shared folders – We already have the secondary mailbox in online only mode.

While this group of users are the main ones affected there are others in the organisation that have freezes too and they aren't using the same secondary mailboxes. It seems to affect users which have a shared mailbox delegated to them or access a mailbox in online only mode.

Other than reducing the mailbox size which seems to be the usual advice, is there anything you can suggest to test connectivity or determine what is causing the Outlook freeze?

Daniel 1 Reputation point

2021-02-17T00:40:37.557+00:00

I have the same issue with frequent freezes on a number of different computers and so far been unable to resolve, I suspect this is a widespread problem.
Brian Coyne 1 Reputation point

2022-04-20T00:48:13.307+00:00

Any resolution here from anyone? Same thing for us with about 5 shared mailboxes
David Jones 101 Reputation points

2022-04-20T02:08:10.3+00:00

For us it was a whole bunch of issues with Outlook, slowing down, freezing and even disconnecting or failing to connect shared mailboxes. Turned out to be Outlook failing to handle updating an Autodiscover reg key value, following a mailbox migration (in this case it was a mailbox defederation migration from GoDaddy MS 365 to Microsoft direct MS 365). The below article fixed the issues for us, despite the fact their symptoms description doesn't quite match. I was eventually pointed to this article after several days of troubleshooting with MS L2 support. I think the key take away for me is that Autodiscover failures can cause this kind of abhorrent behaviour, even if it's something as simple as your clients using a stale DNS record for the Autodiscover hostname (for which I've seen other posts about):
https://learn.microsoft.com/en-us/outlook/troubleshoot/profiles-and-accounts/cannot-connect-web-service-not-working-migrated-to-office-365

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Daniel 1 Reputation point

2021-02-17T00:40:37.557+00:00

I have the same issue with frequent freezes on a number of different computers and so far been unable to resolve, I suspect this is a widespread problem.
Brian Coyne 1 Reputation point

2022-04-20T00:48:13.307+00:00

Any resolution here from anyone? Same thing for us with about 5 shared mailboxes
David Jones 101 Reputation points

2022-04-20T02:08:10.3+00:00

For us it was a whole bunch of issues with Outlook, slowing down, freezing and even disconnecting or failing to connect shared mailboxes. Turned out to be Outlook failing to handle updating an Autodiscover reg key value, following a mailbox migration (in this case it was a mailbox defederation migration from GoDaddy MS 365 to Microsoft direct MS 365). The below article fixed the issues for us, despite the fact their symptoms description doesn't quite match. I was eventually pointed to this article after several days of troubleshooting with MS L2 support. I think the key take away for me is that Autodiscover failures can cause this kind of abhorrent behaviour, even if it's something as simple as your clients using a stale DNS record for the Autodiscover hostname (for which I've seen other posts about):
https://learn.microsoft.com/en-us/outlook/troubleshoot/profiles-and-accounts/cannot-connect-web-service-not-working-migrated-to-office-365

Answer 1

Hi @Scott Gray ,
What's the version of your Outlook(File>Office account>About Outlook), please ensure that your Outlook has updated to the latest version.

We have multiple Outlook 365 users experiencing freezes/white screen from 10 seconds to 5 minutes or more when using a large shared user mailbox

Was this issue occurred only recently?
When did it happened(Only when you drag or delete the emails or others)?
How did you add the shared user mailbox(delegate access on Outlook client, add another account via account setting or add shared mailbox by administrator)?

As I know, when you add shared mailbox by administrator, the mode of these account would be synced with the primary mailbox and we couldn't change it, and we only could change this mode when we add another account via account setting.

Besides, for performance issue itself, due to it would make a copy locally when you work on cache exchange mode, you could access to the data more quickly than online mode, which may cause the differences on performance. And the mailbox size indeed could affect the client performance as you mentioned, when we add a mailbox that is too large, client would be freezing inevitably.

In order to further analyze your issue, please provide me with more information about your configuration and the detail of your issue, so that I could do the same tests on my environment and compare with your situation.

Update:
Did this issue happen to every user who use this mailbox ? Are there any users could work normally? If so, please first check if there are any differences between them.

According to my research, for the error itself, it's suggested to first remove the shared mailbox account and re-add it to test if the issue has any difference. If the issue still exists, I’m afraid the Outlook profile have been corrupted, which may also cause the error, please kindly try to recreate a new profile and re-add your account to test if it's effective.

I also have researched a lot about the limit of mailbox, but it seems to there are just many connection limits in exchange server, such as the MaxCurrentMaiboxSubmissions and MaxConcurrentMailboxDeliveries etc.But they are actually not applied to Exchange Online as the article mentioned like below.

If you are still considering that the limits affect your issue, it's suggested that some users remove this account and just keep few users logging in it to test if it's possible.

I would continue to test and research about this issues, and if I have any updates, I would post back as soon as possible, thanks.

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Scott Gray 96 Reputation points

2020-10-09T00:21:02.603+00:00

Hi @Jade Liang-MSFT

I'll grab a bunch of screenshots for you soon and reply again. Account is added as a second account in Outlook not as a shared mailbox that's been delegated. Office is latest version (just checked for updates). Applying one Windows update now and will provide version numbers shortly.

I'm experiencing another issue on a particularly bad client now where Outlook is unable to open the second mailbox at all and reports Outlook could not connect to the server. I've created another profile and repaired office and problem persists.

Answer 2

Scott Gray 96

Okay after applying 1 Windows update I think the issue of Outlook not being able to connect (paragraph 2 above) has gone away. Still seeing freezing and white screens though. Here are screenshots.

Version of Office 365

Mailbox added as secondary mailbox under accounts

Connections showing no failures

Workstation details

SARA reports problem with active sessions but then all subsequent tests show success...

Scott Gray 96 Reputation points

2020-10-12T22:37:19.34+00:00

Hi @Jade Liang-MSFT

Any further advice? Or can you direct me to someone or somewhere else I should try?

Answer 3

@Jade Liang-MSFT

I think you commented on another thread of mine instead of this one.

Users are now seeing the following when attempting to open the share (user) mailbox:

I now suspect we are hitting a limitation of user mailboxes and Exchange Online. I have found the following articles which mention a session limit of 40 concurrent connections when logged in with the same credentials to M365/ExO:

https://serverfault.com/questions/672493/is-there-a-documented-maximum-number-of-users-you-can-have-connected-to-an-offic
https://techcommunity.microsoft.com/t5/office-365/what-is-the-limit-of-outlook-clients-connected-to-the-same/m-p/145142

Can anyone confirm the limits of ExO when multiple users are connecting to a single mailbox with the same credentials?

Will changing to a Shared Mailbox (with licence as the mailbox is >50GB) resolve this issue?

Is there a way to see the number of connections to a mailbox in Azure to verify if this may be my issue?

Jade Liang-MSFT 9,986 Reputation points Microsoft Employee

2020-10-13T08:42:14.39+00:00

Hi @Scott Gray ,
Sorry for taking so long to reply, I'm still researching about your issues.
Due to the limit of word, I have updated my answers above, please kindly check if it's helpful to you. Thanks for your understanding.

Answer 4

Hi @Jade Liang-MSFT

For completeness, here are answers to your questions - most of which I think I've already covered above:

Was this issue occurred only recently?
When did it happened(Only when you drag or delete the emails or others)?

Seems to happen randomly at all times. Composing or replying, clicking on folders, moving items from folder to folder. Has been ongoing issue for a few months.

How did you add the shared user mailbox(delegate access on Outlook client, add another account via account setting or add shared mailbox by administrator)?

Second account added in Oulook account setting. It's a user mailbox and not a shared mailbox.

As I know, when you add shared mailbox by administrator, the mode of these account would be synced with the primary mailbox and we couldn't change it, and we only could change this mode when we add another account via account setting.

This is the case. Second account via account setting.

Besides, for performance issue itself, due to it would make a copy locally when you work on cache exchange mode, you could access to the data more quickly than online mode, which may cause the differences on performance. And the mailbox size indeed could affect the client performance as you mentioned, when we add a mailbox that is too large, client would be freezing inevitably.

Can't use cached as it's 50GB plus and would take far too long to initially sync and would result in users seeing major delays when things are move, replied to etc. Currently configured in online only mode as explained above.

In order to further analyze your issue, please provide me with more information about your configuration and the detail of your issue, so that I could do the same tests on my environment and compare with your situation.

See above comments and screenshots.

Did this issue happen to every user who use this mailbox ? Are there any users could work normally? If so, please first check if there are any differences between them.

Yes. All users. Added problem of users being completely unable to connect to the mailbox (see my replies above RE this).

According to my research, for the error itself, it's suggested to first remove the shared mailbox account and re-add it to test if the issue has any difference. If the issue still exists, I’m afraid the Outlook profile have been corrupted, which may also cause the error, please kindly try to recreate a new profile and re-add your account to test if it's effective.

See exhaustive list of things tried to resolve issue in original post. Have recreated profiles, re-added account, repaired office, disabled plugins etc. Nothing has worked.

Surely MS has record of the number of concurrent connections allowed to a user mailbox in ExO? Can this please be verified for others encountering similar issues in future? As per links I shared above MS has apparently previously advised others of limitations with user mailboxes. Is this documented anywhere so it can be shared?

We have now made the mailbox a Shared Mailbox and delegated permissions to the users. So far performance seems dramatically improved (that is, no freezing so far) so it would seem concurrent connections to user mailbox may have been the issue but will continue to monitor.

Would appreciate some sort of official confirmation of this if possible!

Thanks,

Scott

Jade Liang-MSFT 9,986 Reputation points Microsoft Employee

2020-10-16T10:28:51.36+00:00

Hi @Scott Gray ,
Thanks for your updating, and glad to see you could work normally with the Shared Mailbox.

For the questions about the limit of concurrent connections allowed to to a user mailbox in ExO, I did lots of research but haven't found any official document mentioned it. But I would continue to research about it and if I have any updates in the future, I would post back.

Thanks for your understanding.

Answer 5

Scott Gray 96

@Jade Liang-MSFT

I everyone, just updating to advise changing the mailbox to a shared mailbox has resolved "Set of folders can not be opened" error. Users continue to experience lockups in Outlook however - screen goes pale/white and non-responsive - and nothing can be done until Outlook is closed and re-opened. One user in particular seems to be affected more than others but the setup is the same across the board.

Current config is to remove and re-add permissions to the shared mailbox with automapping disabled (via PowerShell). Then mailbox added as secondary account using credentials of the user assigned full access and send as permissions.

Any further advice regarding how to resolve regular white screen in Outlook appreciated.

Jade Liang-MSFT 9,986 Reputation points Microsoft Employee

2020-11-13T10:53:28.99+00:00

As I know, there are many possible factors that would cause the "pale/white" screen(such as the lack of Windows update, too large data file or even the PC itself ). I have researched a lot and found an official document that introduces many suggestions about this issue, in order to troubleshoot it, please kindly follow this article and check if it's also helpful to you.
Hope your issues would be resolved soon.

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Multiple users experiencing Outlook 365 freezes/white screen

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