>>>>Use the code given in the link:

 <system.webServer>
>>>>    <staticContent>
>>>>      <remove fileExtension=".woff" /> <!-- In case IIS already has this mime type -->
>>>>      <mimeMap fileExtension=".woff" mimeType="application/x-font-woff" />
>>>>    </staticContent>    
>>>>  </system.webServer>

>>>>
>>>
>>>That code was already in web config. I just need the same for extension woff2.
>>
>>Then you just need to duplicate it and add some '2''s ?
>
>In addition to web.config we have web.Release.config and web.Debug.config. Should I apply similar changes there as well?
>
>UPDATE. Never mind, I don't think these two are used at all - they don't seem to contain correct info anyway.

If they are there then they *will* be used. But it's possible neither contains any relevant transforms (except probably 'debug off' in the release version) - in which case it doesn't matter