Problem:

While testing an existing C# app that connected to our Dynamics 365 environment, we encountered an unusual error after updating the CRM SDK Nuget package used by the app.

System.InvalidCastException: ‘Unable to cast object of type ‘Microsoft.Xrm.Sdk.Entity’ to type ‘XXXX.Xrm.Model.XXXX.’

Here is some sample code to illustrate:

CrmServiceClient conn = new CrmServiceClient("Url=https://myorg.crm6.dynamics.com; Username=XXXXX@XXXXX.com; Password=XXXXXX; authtype=Office365");

IOrganizationService orgService = conn.OrganizationWebProxyClient != null ? (IOrganizationService)conn.OrganizationWebProxyClient : (IOrganizationService)conn.OrganizationServiceProxy;

            using (var context = new CrmServiceCtx(orgService))
            {
                // Do stuff
                var lead = context.LeadSet.First(); // Causes error to occur
            }

Solution

After some investigation, I discovered that the problem had been caused by a recent change in functionality within the CRM SDK Nuget package Microsoft.CrmSdk.XrmTooling.CoreAssembly. 

The SkipDiscovery parameter in the connection string specifies whether to use the Discovery Service. If set to ‘False’ the Discovery Service will be used to find the CRM endpoint address. As of release  9.0.2.7, this value defaults to ‘True’ and causes issues with early bound types.

The solution is to add ‘SkipDiscovery=False’ to your connection string.

CrmServiceClient conn = new CrmServiceClient("SkipDiscovery=False; Url=https://myorg.crm6.dynamics.com; Username=XXXXX@XXXXX.com; Password=XXXXXXX; authtype=Office365");

More information can be found here https://docs.microsoft.com/en-us/dynamics365/customer-engagement/developer/xrm-tooling/use-connection-strings-xrm-tooling-connect

Hope this helps others out there with the same issue.

• About
• Latest Posts

Shane Bartholomeusz

G’day, I’m a technical solutions consultant based in Perth, Australia that specialises in the Microsoft technology stack, including .NET, Dynamics 365, Azure and general web development etc.

This blog is my place to share my thoughts, helpful solutions and just random nerdy stuff.

Latest posts by Shane Bartholomeusz (see all)

• Solved: Build Errors Not Showing in VS 2022 - 21st November 2024
• How To: Configure VSCode to Trust Self-Signed Certs - 16th August 2024
• Solved: GitHub Actions – HTTP 403: Resource not accessible by integration - 13th June 2024