"NetworkError: 404 Not Found fontawesome-webfont.woff?v=4.0.3

This worked for me: Add the following lines to your web.config

<system.webServer>
 <staticContent>
   <remove fileExtension=".woff"/>
   <mimeMap fileExtension=".woff" mimeType="application/x-font-woff" />
 </staticContent>
</system.webServer>

You have to add these lines because by default Apache is not configured with .woff as a default MIME-type. Apache default MIME-type This holds for IIS as well. As Seb Duggan explains here:IIS default MIME, by default .woff files will not be served by the server.

I've updated mime-types in my IIS web server and that resolves my problem.

Extention > .ttf    MimeType > application/x-font-ttf
Extention > .woff   MimeType > application/x-font-woff
Extention > .woff2  MimeType > application/x-font-woff2

I don't need to change anything in web.config. However, IIS will eventually updates web.config.

I solve it also using adding the file type under handlers on your web.config for any application .net, angular etc you can set a web.config on IIS

     <handlers>
     <add name="fonts" path="*.woff" verb="*" preCondition="integratedMode" type="System.Web.StaticFileHandler" />
     <add name="fonts2" path="*.woff2" verb="*" preCondition="integratedMode" type="System.Web.StaticFileHandler" />
     </handlers>