Find exception (Error) when TryUpdateModel fails to update model in ASP.Net MVC

My Code :-

Here in "ModelState.Values" rather then giving the actual error message its showing as 'System.Collections.Generic.Dictionary`2+ValueCollection'

Could you please help me how do I Log the error message If any error occurred in the TryUpdateModel in MVC4.

if (TryUpdateModel(model))
{
    //My Logic
}

else
{
    ActivityLogger.LogActivity("HandleReceiverAddressSubmitted Method" + ModelState.Values);
}