Recently we started noticing this error in the event log for Microsoft Dynamics CRM Email Router. After a bit of research, we found that the issue was occurring because from the authentication providers, of Microsoft Dynamics CRM website, the Negotiate provider was removed. So we had to add the Negotiate provider back. The following are the steps we followed.
- Login to Microsoft Dynamics CRM Application server
- Open IIS and go to Microsoft Dynamics CRM website
- Double click Authentication, select windows authentication and Providers.
- Add the Negotiate provider back.
Please check the screenshot below.
Now the big question. Why removing Negotiate causes this error? The reason for this error is because Dynamics CRM Email router tries to connect to Microsoft Dynamics CRM Organization Service using the WebHttpBinding which does not support NTLM with anonymous authentication.
Off course there can be other reasons for this error, but if you have Negotiate removed from the list of authentication providers, doing the above would help to fix the issue.
Hope this helps!