Inconsistent Accessibility: Parameter type is less accessible than method

I'm trying to pass an object (a reference to the currently logged on user, basically) between two forms. At the moment, I have something along these lines in the login form:

private ACTInterface oActInterface;

public void button1_Click(object sender, EventArgs e)
    {
        oActInterface = new ACTInterface(@"\\actserver\Database\Premier.pad",this.textUser.Text,this.textPass.Text);

        if (oActInterface.checkLoggedIn())
        {
            //user has authed against ACT, so we can carry on
            clients oClientForm = new clients(oActInterface);
            this.Hide();
            oClientForm.Show();
        }
        else...

on the next form (clients), I have:

public partial class clients : Form
{
    private ACTInterface oActInt {get; set;}

    public clients(ACTInterface _oActInt)

...which results in me getting:

Error	1	Inconsistent accessibility: 
parameter type 'support.ACTInterface' is less accessible than method    
'support.clients.clients(support.ACTInterface)'	 
c:\work\net\backup\support\support\clients.cs	20	16	support

I don't really understand what the problem is - both fields are private, and accessed by the relevant public method from the form. Googling doesn't really help, as it just points towards one element being public and the other private, which isn't the case here.

Anybody help?

Constructor of public class clients is public but it has a parameter of type ACTInterface that is private (it is nested in a class?). You can't do that. You need to make ACTInterface at least as accessible as clients.

Make the class public.

class NewClass
{

}

is the same as:

internal class NewClass
{

}

so the class has to be public

If sounds like the type ACTInterface is not public, but is using the default accessibility of either internal (if it is top-level) or private (if it is nested in another type).

Giving the type the public modifier would fix it.

Another approach is to make both the type and the method internal, if that is your intent.

The issue is not the accessibility of the field (oActInterface), but rather of the type ACTInterface itself.

What is the accessibility of the type support.ACTInterface. The error suggests it is not public.

You cannot expose a public method signature where some of the parameter types of the signature are not public. It wouldn't be possible to call the method from outside since the caller couldn't construct the parameters required.

If you make support.ACTInterface public that will remove this error. Alternatively reduce the accessibility of the form method if possible.

parameter type 'support.ACTInterface' is less accessible than method    
'support.clients.clients(support.ACTInterface)' 

The error says 'support.ACTInterface' is less accessible because you have made the interface as private, at least make it internal or make it public.

The problem doesn't seem to be with the variable but rather with the declaration of ACTInterface. Is ACTInterface declared as internal by any chance?

When I received this error, I had a "helper" class that I did not declare as public that caused this issue inside of the class that used the "helper" class. Making the "helper" class public solved this error, as in:

public ServiceClass { public ServiceClass(HelperClass _helper) { } }

public class HelperClass {} // Note the public HelperClass that solved my issue.

This may help someone else who encounters this.

You can get Parameter (class that have less accessibility) as object then convert it to your class by as keyword.

In my case I hadone class in a file and I was passing a instance of that class to the constructor of my form in another file. The problem was had declared the class without the public modifier : class MyClass {}

I could have solved it by changing it to public class MyClass {}

If this error occurs when you want to use a classvariable in a new form, you should put the class definition in the

> Formname.Designer.cs

instead of the Formname.cs file.

After updating my entity framework model, I found this error infecting several files in my solution. I simply right clicked on my .edmx file and my TT file and click "Run Custom Tool" and that had me right again after a restart of Visual Studio 2012.

All the answers that say make the type ActInterface as public are right. I am only putting this post to explicitly mention why that's an issue

If a parameter to your public class constructor is private or internal qualified class, it means you wont be able to create an object of that parameter class from outside of the assembly and when you cannot instantiate the parameter object, how can you call this constructor to instantiate an object of this class ?

Try making your constructor private like this:

private Foo newClass = new Foo();