When you create a class to be used as the model in a .NET MVC application, the class has to have a parameterless constructor. It is called during the POST when the user clicks the submit button of the form. If the class does not have a parameterless constructor, we will get the following generic error message. None of the breakpoints can help you to find the cause, and there is no entry in the event log.
The website cannot display the page HTTP 500 Most likely causes: •The website is under maintenance. •The website has a programming error. What you can try: Refresh the page. Go back to the previous page. More information