MSExchange Autodiscover Error 1 After Exchange 2016 CU23 RRS feed

  • General discussion

  • Hi, After install The latest CU 23 for Exchange 2016 and Latest Security Update KB5014261 the Event Viewer show this error

    Unhandled Exception "Object reference not set to an instance of an object."
    Stack trace:    at Microsoft.Exchange.AutoDiscoverV2.FlightSettingRepository.GetHostNameFromVdir(ADObjectId serverSiteId, String protocol)
       at Microsoft.Exchange.AutoDiscoverV2.AutoDiscoverV2.ExecuteOnPremEndFlow(AutoDiscoverV2Request request)
       at Microsoft.Exchange.AutoDiscoverV2.AutoDiscoverV2.Execute(AutoDiscoverV2Request request, ITenantRepository tenantRepository)
       at Microsoft.Exchange.AutoDiscoverV2.AutoDiscoverV2HandlerBase.<>c__DisplayClass11_0.<ProcessRequest>b__0()
       at Microsoft.Exchange.Common.IL.ILUtil.DoTryFilterCatch(Action tryDelegate, Func`2 filterDelegate, Action`1 catchDelegate)
    How can solve this issue?

    Thursday, July 7, 2022 9:02 AM

All replies

  • Troubleshooting
    Follow the steps below to resolve the autodiscover related issues.

    Make sure you have correct CNAME record configured for autodiscover feature. Follow the Knowledge Base article on
    What Is An Autodiscover Record And Why Do I Need It?
     to have proper instructions.
    Clear DNS cache on your PC or Mac.
    On PC: open Command prompt and type in ipconfig /flushdns. Execute the command.
    On MAC OS X Yosemite: open the Terminal and type in  sudo killall -HUP mDNSResponder. Execute the command.

    Test E-mail AutoConfiguration tool
     in Outlook to review on what step Outlook fails to connect. This provides a good measure of how the user's workstation or network is resolving autodiscover. If you do not see the failed step in the log,  contact Support and provide us the results, so that we could further assist you.
    Run the  Microsoft Remote Connectivity Analyzer, choosing Outlook Autodiscover radio button under Microsoft Office Outlook Connectivity Tests section. This test provides information on how your autodiscover resolves globally. Follow the instructions and provide Support with results of the test.
    If the Autodiscover for your domain resolves correctly, but there is one machine affected where you cannot setup profile automatically or features that depend on autodiscover does not work, modify the hosts file following the Knowledge Base article on 
    How Do I Find And Modify Entries In The HOSTS File?
    If the Autodiscover resolves using your local ActiveDirectory values and does not find the values kept by the DNS hosting provider, follow the steps described in the article
    Why Can't I Connect My Outlook 2016/2019 To Exchange
     to use HTTP redirect method and skip all initial lookups.
    Note: the article provided in this step helps to resolve the issue of incorrect DNS resolution for all working stations included to your domain in case you were utilizing on-premises Exchange prior to migration of your mailboxes to Intermedia.
    If the test shows that autodiscover resolution fails due to a presence of an XML file on your website, contact your web developer to remove the files. As a temporary workaround you can use the steps described in the article
    Why Can't I Connect My Outlook 2016/2019 To Exchange
     to use HTTP redirect method and skip all initial Autodiscover resolution steps.
    If you have an existing Outlook profile and you utilize Outlook 2010 or 2013, which were set up manually or with Outlook Profile Helper, in Outlook navigate to File > Account Settings > Account Settings > Change > More Settings > Connection > Exchange Proxy setting and make the following changes:
    Switch Basic Authentication to NTML Authentication
    Check Only connect to proxy servers that have this principal name in their certificate check box
    Type, where XXX depends on your proxy server information.
    Important: to protect your account information we cannot publish your Server names in public Knowledge Base. You can find your Exchange Proxy Server by navigating to HostPilot > Home >Exchange Servers and Settings > Exchange Proxy Server
    Then you will get a security prompt, check the box Don’t ask me about this website again and then click Allow. Note: If your autodiscover record is incorrect, then these steps may be reverted some time later by the autodiscover process in Outlook. Therefore, it is best to make sure that your global autodiscover record is correct, as this may only be a temporary fix.


    Ross Smith

    Tuesday, August 9, 2022 5:36 AM
  • Hello,

    For this operation, you need to check the DNS and VD.

    Get-AutodiscoverVirtualDirectory -server "ExchangeServerName" | fl name, *url*

    Get-AutodiscoverVirtualDirectory -Server "ExchangeServerName" |set-AutodiscoverVirtualDirectory -ExternalUrl https://autodiscover.FQDN/Autodiscover/Autodiscover.xml
    Tuesday, August 9, 2022 6:58 AM