Asp.Net Core - Conversion failed when converting from a character string to uniqueidentifier

I am using the Asp.Net Core sample application from Auth0’s GitHub and have configured it.

When I login with a bad username/password, I correctly get back a “Bad username or password” error.

When I use a correct username and password, I get the GetTokenAsync() error " * Conversion failed when converting from a character string to uniqueidentifier."

The database works as when I press the Try It button in the dashboard, I can authenticate.

Here’s the code

                 var resourceOwnerTokenRequest = new ResourceOwnerTokenRequest
                {
                    ClientId = _configuration["Auth0:ClientId"],
                    ClientSecret = _configuration["Auth0:ClientSecret"],
                    Scope = "openid profile",
                    Realm = "MyDatabaseHere",  
                    Username = vm.EmailAddress,
                    Password = vm.Password
                };
                var result = await _client.GetTokenAsync(resourceOwnerTokenRequest);