“Reference cannot be resolved” error

This article is contributed. See the original author and article here.

While trying to make a WCF service to connect Dynamics 365, I came across to this error message:

 

Message Metadata contains a reference that cannot be resolved: ‘https://dynamics.com/test.svc?wsdl&sdkversion=9’. >> StackTrace at System.ServiceModel.Description.MetadataExchangeClient.MetadataRetriever.Retrieve(TimeoutHelper timeoutHelper)rn

 

We also saw the error below during testing:

 

InnerException System.Net.WebException: Unable to connect to the remote server —> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond

 

Root Cause

 

Dynamics 365 started requiring TLS 1.2 after version 9.x (Reference). Connections that don’t use TLS 1.2 started failing after this update.

 

Solution

 

Force WCF service to use TLS 1.2 to solve this issue:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

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