UI-Router cause issues with bottom navbar

Hi I’m using this snippet for a bottom nav-bar

  <div class="tabs tabs-icon-top">
  <a class="tab-item" ui-sref="main.home">
    <i class="icon ion-home"></i>
    Home
  </a>
  <a class="tab-item" ui-sref="main.fav">
    <i class="icon ion-star"></i>
    Favorites
  </a>
  <a class="tab-item" ui-sref="main.set">
    <i class="icon ion-gear-a"></i>
    Settings
  </a>
</div>

And when I start to move between pages it works until it crush and does not change state with this giving error:

[Error] TypeError: null is not an object (evaluating 'parent.insertBefore')
(anonymous function) (ionic.bundle.js, line 10647)
forEach (ionic.bundle.js, line 7950)
after (ionic.bundle.js, line 10646)
(anonymous function) (ionic.bundle.js, line 10735)
enter (ionic.bundle.js, line 11843)
enter (ionic.bundle.js, line 30252)
(anonymous function) (ionic.bundle.js, line 39748)

What can I do?

Thanks

The problem was with the ui-router state definition. 2 states had the same url.