There isn't an error. It just opens in the current window that is open. I want it to open a website into a new window. Or just a way to switch between tabs, which I don't know if that's possible or not.
The way things are designed it isn't very easy to hijack the user's preferences and open a new window. Letting the user's running browser decide how to do it is the way it should work.
Anything beyond that is playing in no-man's land. If you wish to target specific browsers you can use extant command-line options: