One windows 2016 terminal server user account cannot connect with outlook2016

Question

We have an windows 2016 machine terminal server running MS Datacenter 2016.We have a hybrid infrastructure with exchange cu23 with march security update Users whe hjave un hybrid.They have E1 licenses.The mailboxes have all been migrated to O365.Users are synchronized with AAD connect. Recently, a single user started having issues with Outlook desktop. I am not able to create a new mail profile for her while logged into the server as her or when logged in with the admin account. I have gotten these errors:

-Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. Microsoft Exchange is currently busy.

-Outlook cannot log on. Verify you are connected to the network and are using the proper server and mailbox name. The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.

If I try to set up a mail profile for her account on a regular computer, it works.

I set up a new account for a different employee on the same server and it worked.

I tried creating an alias for her account and using that to set up a mail profile on the terminal server, and it did not work (while logged in as her or as the admin account).

I ran Microsoft Remote Connectivity Analyzer with modern authentication on her account, and it fails at "Testing MAPI over HTTP connectivity to server outlook.office365.com." I don't know if this is the cause of the problem, but here is part of the output:

Testing the address book "Check Name" operation for user [xxx@****] against server outlook.office365.com.

An error occurred while attempting to resolve the name.

Additional Details

A protocol layer error occured. HttpStatusCode: 500

Failure LID: 47372

Failure Information:

REQUEST ...

POST /mapi/nspi/?mailboxId=[removed] HTTP/1.1

Content-Type: application/octet-stream

User-Agent: MapiHttpClient

Authorization: Bearer [truncated] ...

ClientApplication: MapiHttpClient/ ... X-RequestType: Bind Host: outlook.office365.com Content-Length: 45

--- REQUEST BODY [+0.010] --- ..[BODY SIZE: 45] --- REQUEST SENT [+0.010] --- ###### RESPONSE [+0.239] ###### HTTP/1.1 500 request-id: ... X-RequestType: Bind x-ms-diagnostics: 2000007;reason="Type with name 'Microsoft.Exchange.Data.Directory.VariantConfiguration.ABComparison.ILdapWriteABComparisonHelperSettings' is not found. Please check spelling and that necessary assembly is loaded in the AppDomain.";error_category="internal_error" ... X-FailureContext: BackEnd;500;;;;;

X-RequestType: Bind x-ms-diagnostics: 2000007;reason="Type with name 'Microsoft.Exchange.Data.Directory.VariantConfiguration.ABComparison.ILdapWriteABComparisonHelperSettings' is not found. Please check spelling and that necessary assembly is loaded in the AppDomain.";error_category="internal_error" ... error="invalid_token" X-Powered-By: ASP.NET HTTP Status Code: 500 InternalServerError

Answer 1

Hi @pazzoide76 ，

According to your description, we would like you to give an attempt for following steps:

Fully quit Outlook > Windows Start > Type regedit.exe > OK > Select the following key in registry:

HKEY_CURRENT_USER\Software\Microsoft\Exchange

Right-click MapiHttpDisabled > click Modify > Change the Value data to 0 > OK > Restart Outlook

In addition, make sure your Outlook app has the latest updates installed.

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". 

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.

Answer 2

The problem returned by itself so it was a temporary problem on the O365 side.

Thank you

Greetings