So if you ever attempt to go from http to https (or vice versa) on your CRM environment be aware that you may face the following issue with your XRM Services if you have multiple bindings set in IIS:
WebHost failed to process a request. Sender Information: System.ServiceModel.ServiceHostingEnvironment+HostingManager/12547953 Exception: System.ServiceModel.ServiceActivationException: The service '/Dev/XRMServices/2011/Organization.svc' cannot be activated due to an exception during compilation. The exception message is: The value could not be added to the collection, as the collection already contains an item of the same type: 'System.ServiceModel.Description.UseRequestHeadersForMetadataAddressBehavior'. This collection only supports one instance of each type. Parameter name: item. ---> System.ArgumentException: The value could not be added to the collection, as the collection already contains an item of the same type: 'System.ServiceModel.Description.UseRequestHeadersForMetadataAddressBehavior'. This collection only supports one instance of each type. Parameter name: item at System.Collections.Generic.KeyedByTypeCollection`1.InsertItem(Int32 index, TItem item) at Microsoft.Crm.Extensibility.SdkServiceEndpointBuilder.AddDefaultPorts(ServiceHost serviceHost, PortSchemeDictionary portSchemes) at Microsoft.Crm.Extensibility.SdkServiceEndpointBuilder.AddDefaultEndpoint(ServiceHost serviceHost, Type implementedContract) at Microsoft.Crm.Extensibility.SdkServiceEndpointBuilder.BuildEndpoints(ServiceHost serviceHost, Type implementedContract, Func`1 messageInspectorFactory) at Microsoft.Crm.Extensibility.SdkServiceHost.InitializeRuntime() at System.ServiceModel.ServiceHostBase.OnOpen(TimeSpan timeout) at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout) at System.ServiceModel.ServiceHostingEnvironment.HostingManager.ActivateService(ServiceActivationInfo serviceActivationInfo, EventTraceActivity eventTraceActivity) at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath, EventTraceActivity eventTraceActivity) --- End of inner exception stack trace --- at System.ServiceModel.ServiceHostingEnvironment.HostingManager.EnsureServiceAvailable(String normalizedVirtualPath, EventTraceActivity eventTraceActivity) at System.ServiceModel.ServiceHostingEnvironment.EnsureServiceAvailableFast(String relativeVirtualPath, EventTraceActivity eventTraceActivity) Process Name: w3wp Process ID: 8388
Why you ask?! This is due to the fact that CRM is quite finicky about only wanting one particular binding for the CRM instance. Having the multiple bindings without properly setting it up will cause some conflicts (starting with the one above). So the solution here is to ensure you only have one binding in IIS. Once you have your bindings set up properly be sure to perform an IISRESET on the web server. This should resolve the error and make the XRMServices play nice. If it does not check to make sure you do not have any hard-coded values of URLs or ports anywhere. Hope this helps.
@JaredMeredith 