C++ open a new Form from another Form won’t work (Winform)

  c++, forms, windows, winforms

First of all sorry for my english,
I just started coding in c++ few weeks ago, i’m trying to do an UI Form to manage an SQL database for my engineering school project.
I just have one problem i cant solve, i looked everywhere on the net but no answere…
I would like to do an authentify form with username and password but when I include my "Authentify.h" to my main "Interface.h" after the pragma once, i get theses errors when I execute debug :


and these too :


by the way, I tryed use

Authentify^ form = gcnew Authentify;


in my Interface.h, in the Interface(void) definition so the Authentify Form can pop up at start, but as long as the #include "Authentify.h" give me errors, i cant open the Authentify Form.


as you can see, VS tell me that there is no problem detected till I execute debug
here you cant find my code (Interface.h is 1700 lines long but its only Winform fonctions)


thanks a lot for any help,

Source: Windows Questions