Exchange server 2016 Free/busy issue with event ID 4002

Question

We also get the event 4002 on both the servers when free/busy issues persists

Process 7788: ProxyWebRequest CrossSite from S-1-5-21-3348653359-2351925770-1694656208-11937 to https://shnvwmbx004.xxx.com:444/ews/exchange.asmx failed. Caller SIDs: NetworkCredentials. The exception returned is Microsoft.Exchange.InfoWorker.Common.Availability.ProxyWebRequestProcessingException: 代理 Web 请求失败。 ---> System.Net.WebException: 请求被中止: 请求已被取消。
在 System.Web.Services.Protocols.WebClientAsyncResult.WaitForResponse()
在 System.Web.Services.Protocols.WebClientProtocol.EndSend(IAsyncResult asyncResult, Object& internalAsyncState, Stream& responseStream)
在 System.Web.Services.Protocols.SoapHttpClientProtocol.EndInvoke(IAsyncResult asyncResult)
在 Microsoft.Exchange.InfoWorker.Common.Availability.Proxy.Service.EndGetMailTips(IAsyncResult asyncResult)
在 Microsoft.Exchange.InfoWorker.Common.MailTips.MailTipsApplication.EndProxyWebRequest(ProxyWebRequest proxyWebRequest, QueryList queryList, IService service, IAsyncResult asyncResult)
在 Microsoft.Exchange.InfoWorker.Common.Availability.ProxyWebRequest.EndInvoke(IAsyncResult asyncResult)
在 Microsoft.Exchange.InfoWorker.Common.Availability.AsyncWebRequest.EndInvokeWithErrorHandling()
--- 内部异常堆栈跟踪的结尾 ---
. Name of the server where exception originated: SHNVWMBX002. LID: 43532. Make sure that the Active Directory site/forest that contain the user's mailbox has at least one local Exchange 2010 server running the Availability service. Turn up logging for the Availability service and test basic network connectivity.

Answer 1

We are also experiencing this same issue in our Exchange 2016 CU21 environment. We have two servers in a DAG. If a users mailbox is is hosted on server A then Busy/Free information does not populate in scheduling assistant for any user who's mailbox is hosted on server B and vice versa. If they are hosted on the same server scheduling assistant works correctly.
The virtual directory is populated correctly in Exchange admin center for both servers. I can also browse to the virtual directory in Edge from the client machines with no problems. The SSL is valid. Authentication is set up for Anonymous and Windows for EWS in Exchange Back End on both servers.
One thing I find odd is that the error logged in Event Viewer logs the virtual directory URL using the machine name NOT what is set in Exchange Admin Center.

Possibly and issue with InternalNLBBypassUrl? I have tried setting it to various URLs to no avail.

Any help would be appreciated! I am out of ideas.

Answer 2

Hello,

I know this post is a bit older. How was the problem solved ? What was the cause ?

Thank you very much !

Answer 3

Hello,

Is TLS 1.2 being used?
Are the registry keys for TLS 1.2 available?
https://techcommunity.microsoft.com/t5/exchange-team-blog/exchange-server-tls-guidance-part-2-enabling-tls-1-2-and/ba-p/607761

What does the scan with DevTools F12 in the browser show?
https://techcommunity.microsoft.com/t5/exchange-team-blog/demystifying-hybrid-free-busy-finding-errors-and-troubleshooting/ba-p/607727

Thank you!

Answer 4

Hello,

I know this post is a bit older. How was the problem solved ? What was the cause ?

Thank you very much !