FOSRestBundle with QueryParam or ParamConverter not working - symfony

Question

I'm having a problem with FOSRestBundle. Everything was working fine, until I added the #QueryParam annotation (on my cgetAction method) and the #ParamConverter annotation (on my getAction method). I have no idea what could be wrong, but the error I'm getting back is this...
The format "" is not supported for deserialization.
415 Unsupported Media Type - UnsupportedMediaTypeHttpException
The point of failure so to speak is here:
vendor\friendsofsymfony\rest-bundle\FOS\RestBundle\Request\AbstractRequestBodyParamConverter.php at line 118
My annotations for the specific controller are as follows (I'm just posting the cgetAction as I'm sure they are related somehow, I just don't know how)
/**
* Lists all School entities.
*
* #QueryParam(name="page", requirements="\d+", default="1", description="Current page of school listing")
* #View(template="LMSSchoolBundle:School:index.html.twig", templateVar="pagination")
*/
public function cgetAction(ParamFetcher $fetcher)
{
$em = $this->getDoctrine()->getManager();
$entities = $em->getRepository('LMSSchoolBundle:School')->createQueryBuilder('s');
$pagination = $this->get('knp_paginator')->paginate(
$entities,
$fetcher->get('page'),
$this->container->getParameter('page_item_limit')
);
$groups = ($this->get('security.context')->isGranted('ROLE_API')) ? 'restapi' : 'standard';
$view = $this->view($pagination)
->getSerializationContext()
->setGroups($groups);
return $view;
}
And finally, the fos_rest section of my config.yml:
fos_rest:
routing_loader:
include_format: false
body_converter:
enabled: true
validate: true
validation_errors_argument: validationErrors
param_fetcher_listener: true
body_listener:
decoders:
json: fos_rest.decoder.jsontoform
xml: fos_rest.decoder.xml
allowed_methods_listener: true
access_denied_listener:
json: true
disable_csrf_role: ROLE_API
view:
formats:
json: true
rss: false
xml: true
templating_formats:
html: true
force_redirects:
html: true
failed_validation: HTTP_BAD_REQUEST
default_engine: twig
view_response_listener: 'force'
format_listener:
rules:
- { path: '^/css', priorities: [ 'css' ], fallback_format: false, prefer_extension: true }
- { path: '^/js', priorities: [ 'js' ], fallback_format: false, prefer_extension: true }
- { path: '^/', priorities: [ 'html', 'json', 'xml' ], fallback_format: html, prefer_extension: true }
- { path: '^/', host: 'api.%domain%', priorities: [ 'json', 'xml' ], fallback_format: json, prefer_extension: false }
NOTE - The ^/css and ^/js rules are in there because the bundle was messing with my layouts and such, don't know if that's the proper way to do it? I really don't know if this whole config section is even correct! The documentation is pretty complex, IMHO.
Anyway, if I remove the #QueryParam annotation, it continues into the function without an issue. But if I add it, the application exits before it even reaches $em = $this->...
Thanks for any help!
EDIT Oh and by the way, I have thought of the fact that this could be related to the JMSSerializer, but the website seems to be down at the moment (in South Africa at least), so yeah...