Hello everybody,
I've installed Facebook plugin on 3.8 NopC store.
When I try to login i riceved this error:

We're sorry, an internal error occurred.

Our supporting staff has been notified of this error and will address the issue shortly.

We apologize for the inconvenience.

Please try clicking your browsers 'back' button or try reloading the home page.

If you continue to receive this message, please try again in a little while.

Thank you for your patience.

And in the log:

System.Net.WebException: Errore del server remoto: (400) Richiesta non valida. in System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request) in System.Net.WebClient.DownloadString(Uri address) in DotNetOpenAuth.AspNet.Clients.FacebookClient.QueryAccessToken(Uri returnUrl, String authorizationCode) in DotNetOpenAuth.AspNet.Clients.OAuth2Client.VerifyAuthentication(HttpContextBase context, Uri returnPageUrl) in Nop.Plugin.ExternalAuth.Facebook.Core.FacebookProviderAuthorizer.VerifyAuthentication(String returnUrl) in Nop.Plugin.ExternalAuth.Facebook.Core.FacebookProviderAuthorizer.Authorize(String returnUrl, Nullable`1 verifyResponse) in Nop.Plugin.ExternalAuth.Facebook.Controllers.ExternalAuthFacebookController.LoginInternal(String returnUrl, Boolean verifyResponse) in Nop.Plugin.ExternalAuth.Facebook.Controllers.ExternalAuthFacebookController.LoginCallback(String returnUrl) in lambda_method(Closure , ControllerBase , Object[] ) in System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) in System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) in System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) in System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) in System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d() in System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() in System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() in System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() in System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() in System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult) in System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() in System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) in System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) in System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) in System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) in System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) in System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) in System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) in System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() in System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)


Cloud You help me?

If you wanna try: www.comolakewine.com

Thanks

Marco