Misago/misago/emberapp/app/templates/error-403.hbs

<div class="error-page error-403">
  <div class="container">
    <div class="error">

      <div class="error-icon">
        <span class="fa fa-ban"></span>
      </div>

      <div class="error-message">
        {{#if message}}
        <p class="lead">{{message}}</p>
        {{else}}
        <p class="lead">{{gettext "You don't have permission to access this page."}}</p>
        {{/if}}
      </div>

    </div>
  </div>
</div>