Help with Railroady

I did mange to install railroady, and when I do ‘rake diagram:all’ and ‘open doc/*.svg’ I do see some diagrams, but no instance variables or inheritance connections.

When I do something like

‘railroady -i -o controller.png -c’ or ‘railroady -i -C | neato -Tpng > controllers.png’ it generates a png that can’t be opened or a png that is just the same as before (without instance variables or inheritance)

Please help me

Thank you,

Rodrigo