No parameterless constructor defined for this object. in ASP.NET MVC Controller

Question

I am sure this is quite straightforward but I am a bit stuck here. The routing defined for my app is just the default. I have the following controller defined.

Answer 1

If DocumentEditViewModel constructor's accessibility level is protected you will get also the same error.

Answer 2

Most likely you have dependency injections mechanism. But MVC requires "special" way to register container. Look at this link Adding Unity to Your Web Applications, patterns and practices

Answer 3

I had a slightly different problem. One of my Model classes was abstract.

Answer 4

add to class DocumentEditViewModel default constructor

public DocumentEditViewModel (){}

Answer 5

The MVC framework is trying to create an instance of the DocumentViewModel class but it can't find a publicly accessible default constructor (that does not take any arguments). You can either define such a default constructor like @simplyDenis suggested or define a cusotm ModelBinder that can create the instance using your custom constructor.

Answer 6

Does DocumentEditViewModel have a parameterless constructor? I believe this is needed for modelbinding on your post view.