Ember GET to Rails backend

I have this json rails api endpoing that response to GET-last-problems => /api/v1/last-problems

{"last_problems": [
    {
    "id": 1,
    "name": "Who are you?",
    "description": ""
},
{
    "id": 2,
    "name": "Who are they?",
    "description": ""
}
}

and when from ember I call to last-problems I have this:

GET http://localhost:3000/api/lastProblems 404 (Not Found)
Error while processing route: last_problems.index Adapter operation failed Error: Adapter operation failed

I read that Ember camelize and clean rails routes.

Do I need an adapter? Where do I have to created it?