I can see icon-screenshot, icon-map-marker being rendered fine but don't see anything when using icon-paper-clip or icon-group or icon-link ... what could possibly be wrong? Anyone here experienced the same issue?
Based on the official troubleshooting guide these are the things you should check:
General
- You don't have an old version of Font Awesome installed on your system (it may have priority);
- [If you are serving Font Awesome from your own server] Both your font-awesome.css file and your /fonts folders are up to date;
- [If you are serving Font Awesome from a CDN] Your css link is up to date;
- You are not using plugins/extensions loading older/modified versions of Font Awesome;
- You are using valid HTML5 templates;
- Your browser's development console shows that you are loading the proper font files;
- Your browser's extensions are not blocking webfonts (noscript, adblockplus, etc.).
IE specific
Internet Explorer compatibility mode might cause some issues. Disable it by adding to your head:
<meta http-equiv="X-UA-Compatible" content="IE=edge">If you are using IE8, it's necessary to add the html5.js script like:
<!--[if lt IE 9]> <script src="http://cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.2/html5shiv.min.js"></script> <![endif]-->FontAwesome is not compatible with ie7-js.
Internet Explorer generates an error unless the font is set to Installable Embedding mode. More info.
Wordpress specific
Wordpress automatically adds a
<br>tag at the end of the line and this will break icon stacks. Please put your html in one line or add to your stylesheet:.fa-stack br { display: none }
When you are upgrading the fontawesome version, please make sure that you replace css files as well as fonts. If you placed fonts folder in different location, you need to update the path in css files too.
来源：https://stackoverflow.com/questions/15556014/some-font-awesome-icon-not-displaying