title: Cannot read property 'toResolveHierarchy' of undefined
body: <p>I call the <code>i18next</code> change Language function by passing the language code (en-UK) like that : </p>
  
  <pre><code>var changeLng = function (varLng) {  
    i18next.changeLanguage('en', (err, t) =&gt; {
      if (err) return console.log('something went wrong loading', err);
      t('applog'); // -&gt; same as i18next.t
    });
  };
  </code></pre>
  
  <p>I got the following issue : </p>
  
  <pre><code>VM4081 i18next.js:1912 Uncaught TypeError: Cannot read property 'toResolveHierarchy' of undefined
      at setLng (VM4081 i18next.js:1912)
      at I18n.changeLanguage (VM4081 i18next.js:1927)
      at changeLng (VM4079 langUK.js:23)
      at HTMLImageElement.&lt;anonymous&gt; (VM4079 langUK.js:8)
  </code></pre>
  
  <p>I assume that Something going wrong when <code>i18next</code> tries to execute that :</p>
  
  <pre><code>_this4.languages = _this4.services.languageUtils.toResolveHierarchy(l);
  </code></pre>
  
  <p>But I can't see what's needed to properly execute this.
  Thanks in advance for your support,
  Jack</p>