When I do Form::open('path/to/controller') it does generate the following path: website.com/path/to/controller , atm. I don't use the mod_rewrite yet so my website controllers are accessible through the index.php, just like website.com/index.php/path/to/controller/. The problem is that the Form::open doesn't recognize such behaviour and its supposing to use the mod_rewrite path..
Is the 'welcome' a controller in the 'app/classes/controller/welcome.php' and you have used the var_dump right in the action_index()?
I am using a account.php controller, which has action_index.php function containing the var_dump, while viewing it, I can see the view etc. but var_dump(Uri::segments()) returns NULL;