Can a creature that is immune to magic (like a will'o wisp) ba harmed by magical weapons. I don't seem to be able to find a ruling on that.
The description of such abilities normally go into detail. Magic weapons do work.
Immunity to Magic (Ex) Will-o'-wisps are immune to all spells and spell-like abilities that allow spell resistance, except magic missile and maze.
A magic weapon is not a spell, not SLA that allows for spell resistance. Those are the only magical things it is immune to. Everything else is fair game.
thanks.