Problem html display

[krzischp]

I installed everything without using sudo. But when I run the server (rails server) and go to localhost:3000, I get many html display problems. For example, the button New Model (when creating a channel) doesn't display. Instead of this, I get New Model.
And when I click on the button, I get (when inspecting) the following error:
SyntaxError: missing } after property list

But then, when I run sudo firefox in the terminal, and visit localhost:3000, I don't have any html display problem.
How can I solve this?

Thanks in advance for your help!