We think it's because the external_link.png is missing. How should I get that file where it's supposed to be?
try running `wagn update` (in your deck directory).
external_link.png is in public/assets in your gem directory. running `wagn update` will make a symlink from public/assets in your deck directory to the one in your gem directory.
(You could also run `rake wagn:update_assets_symlink`, but `wagn update` is much easier to remember)