font-awesome not working bundleconfig in MVC5

I had the same error message and fixed after setting mime types for web fonts in IIS .

My solution was simple: run PM> Install-Package FontAwesome, and reference the correct path:

.Include("~/Content/font-awesome.min.css")

Try using CssRewriteUrlTransform when bundling:

bundles.Add(new StyleBundle("~/Content/css").Include(
        "~/Content/bootstrap.css",                        
        "~/Content/body.css",
        "~/Content/site.css",
        "~/Content/form.css"
    ).Include("~/Content/font-awesome-4.0.3/css/font-awesome.css", new CssRewriteUrlTransform());

This changes any urls for assets from within the css file to absolute urls so the bundling doesn't mess up the relative path.

Docs for CssRewriteUrlTransform