Unknown "pagerfanta" function
That looks like you've forgotten to add the WhiteOctoberPagerfantaBundle to the AppKernel.php, causing that PagerfantaExtension is not loaded, therefore the {{ pagerfanta() }} function is not defined.
$bundles = array( // ... new WhiteOctober\PagerfantaBundle\WhiteOctoberPagerfantaBundle(),);
I guess you have a typo somewhere near rendering this template. Add rendering code to your question, it should like like this.
https://github.com/whiteoctober/WhiteOctoberPagerfantaBundle#rendering-pagerfantas
$adapter = new DoctrineORMAdapter($queryBuilder);$pagerfanta = new Pagerfanta($adapter); return $this->render('@YourApp/Main/example.html.twig', [ 'my_pager' => $pagerfanta,]);