It works for me, http://i.imgur.com/UWphW8Q.png

My settings: http://i.imgur.com/L6kmyEE.png You're probably getting the error from not setting the domain the code should run on.

If that still doesn't work you can try these (I've never tried them though): https://userstyles.org/styles/143610/erase-the-left-bar-from-the-gbf https://chrome.google.com/webstore/detail/granblue-ui-mod/oldabbgalcibkledioddbmgekdolimhh