[Lazarus] converted Delphi 7 project: add new form not possible?

[John Landmesser]

.. and now the most interesting part:

Try to show form2 with the button on Delphi 7 converted form.

Before that add under implementation section:
uses unit2;

Now i get the AV-Error message if i try to show form2!

You too see an error mesage?