Pon el create en primer lugar.
O mejor aún, usa rutas REST:
Código yml:
Ver originallist_halls:
path: /admin/hall
defaults: { _controller: HallBundle:Hall:list }
methods: [GET]
details_hall:
path: /admin/hall/{id}
defaults: { _controller: HallBundle:Hall:details }
methods: [GET]
update_hall:
path: /admin/hall/{id}
defaults: { _controller: HallBundle:Hall:update }
methods: [PUT]
delete_hall:
path: /admin/hall/{id}
defaults: { _controller: HallBundle:Hall:delete }
methods: [DELETE]
create_hall:
path: /admin/hall
defaults: { _controller: HallBundle:Hall:create }
methods: [POST]