I see. The issue here is that framework builder automatically updates any links that occur in the html, but can't update the server redirect page. This means that the path to the redirect page has to be relative to the page it is included on, and not the plugin itself.
The simple solution is to update line 32 where it says:
$GotToPage = "../thank_you_basic_form.php";
and make it say:
$GoToPage = "thank_you_basic_form.php";
That will make it work in this case, but hurts the portability of the code.... since you can not effectively plug it into any subdirectory pages.
A more elegant, though more complex solution would be to use a redirect like:
<?php echo(rel2abs("../thank_you_basic_form.php",dirname(__FILE__))); ?>
This will use the library file to convert the redirect link reference to be relative to the page it is plugged into. This slightly more complex syntax should keep the plugin fully portable, and could be similarly used in other server behaviors when applied to plugins.
We will likely account for this in future versions of the extensions now that the framework builder is released.
