Opening the debug console in Chrome, or even looking at the html source file (after it is loaded in the browser), make sure that all the paths there are valid (i.e. when you follow a link you get to it's content, and not an error). When something is not valid, fix the path (e.g. get rid of the server specific part and make sure you only refer to files that are part of your extension through paths like /js/jquery-123-min.js
).