Windows Form using C++/CLI

I had created a parent form. I initially got the error:

The data necessary to complete this operation is not yet available.

(Exception from HRESULT: 0x8000000A)

which had been solved by adding the following code to the .cpp file:

using namespace System::Windows::Forms;

[STAThread]
void Main(array<String^>^ args) 
{

    Application::EnableVisualStyles();
    Application::SetCompatibleTextRenderingDefault(false);
    MDIpractice::Form1h form;
    Application::Run(%form);
}

Now when I create a new form I don't know what to add in the .cpp file in order to remove the error.