WCF failures occur when Dynamics 365 clients communicate through a load balancer

This article provides a resolution for the issue that you may receive errors from WCF-based clients when Microsoft Dynamics 365 web servers are configured to communicate via a load balancer.

Applies to:   Microsoft Dynamics CRM 2011, Microsoft Dynamics CRM 2013
Original KB number:   2981140

Symptoms

When Microsoft Dynamics 365 web servers are configured behind a load balancer, exceptions may occur from WCF-based clients such as the Outlook Client, Email Router, or SDK applications when communicating over web services. Examples of these exceptions may include:

An unsecured or incorrectly secured fault was received from the other party
SecurityContextException

Cause

The issue occurs due to missing or incorrectly configured persistence settings on the load balancer, which can cause WCF failures when the web server attempts to read a token that was issued by a different web server.

Resolution

Microsoft Dynamics 365 requires IP-based persistence to be configured on the load balancer.