Workflow Services error: "Operation is not implemented by the service"

I been trying to solve this Workflow Services error on my IssueTracker project for 2 weeks without any progress.

Operation is not implemented by the service.
at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)\r\n   at

System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)\r\n   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs)\r\n   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)\r\n   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)\r\n\r\nException rethrown at [0]: \r\n   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)\r\n   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)\r\n   at IssueTrackerTest.IssueProcessService.IIssueProcess.ProcessIssue(Issue issue)\r\n   at IssueTrackerTest.IssueProcessService.IssueProcessClient.ProcessIssue(Issue issue) in C:\\Workspace\\Projects\\IssueTracker\\IssueTrackerTest\\Service References\\IssueProcessService\\Reference.cs:line 285\r\n   at IssueTrackerTest.IssueProcessTest.TestProcessIssue() in C:\\Workspace\\Projects\\IssueTracker\\IssueTrackerTest\\IssueProcessTest.cs:line 88″    string

 

Until today I found this blog post by Damir Dobric.

While invoking an operation on the workflow’s web service you may get following error:

“Operation is not implemented by the service.”

To solve the problem take a look on the ContextToken property of the receive-activity of the workflow service.
If this property is set as shown on the picture below, remove the value, rebuild solution and start all again.

 

Thanks Damir for saving my days