Hi there,

This request is returning French information for me:

travisbell$ curl -v "https://api.themoviedb.org/3/movie/248507?api_key=###&language=fr"
*   Trying 54.83.63.37...
* Connected to api.themoviedb.org (54.83.63.37) port 443 (#0)
* TLS 1.2 connection using TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
* Server certificate: *.themoviedb.org
* Server certificate: RapidSSL SHA256 CA
* Server certificate: GeoTrust Global CA
> GET /3/movie/248507?api_key=###&language=fr HTTP/1.1
> Host: api.themoviedb.org
> User-Agent: curl/7.43.0
> Accept: */*
>
< HTTP/1.1 200 OK
< Access-Control-Allow-Origin: *
< Cache-Control: public, max-age=28800
< Content-Type: application/json;charset=utf-8
< Date: Thu, 23 Mar 2017 19:23:52 GMT
< ETag: "d8ff7b9cd6f29de023ad7367e5961f92"
< Server: openresty
< Status: 200 OK
< Vary: Accept-Encoding
< X-Memc: HIT
< X-Memc-Age: 27530
< X-Memc-Expires: 1270
< X-Memc-Key: d8e65e6ddb86704cb3b8cdc27669e74f
< X-RateLimit-Limit: 40
< X-RateLimit-Remaining: 39
< X-RateLimit-Reset: 1490297042
< Content-Length: 1478
< Connection: keep-alive
<
* Connection #0 to host api.themoviedb.org left intact

And the content from hat request (slightly truncated):

{
  "adult": false,
  "backdrop_path": "/anbyB6Aw4AaAFplCGfT4ODZ0lNZ.jpg",
  "belongs_to_collection": null,
  "budget": 0,
  "genres": [
    {
      "id": 35,
      "name": "Comédie"
    }
  ],
  "homepage": "",
  "id": 248507,
  "imdb_id": "tt3421514",
  "original_language": "fr",
  "original_title": "Supercondriaque",
  "overview": "Romain Faubert est un homme seul qui, à bientôt 40 ans, n’a ni femme ni enfant. Le métier qu’il exerce, photographe pour dictionnaire médical en ligne, n’arrange rien à une hypocondrie maladive qui guide son style de vie depuis bien trop longtemps et fait de lui un peureux névropathe.",
  "popularity": 1.171125,
  "poster_path": "/b4fFxsZvCxH16raJwf7PRMGiy4E.jpg",
  "production_companies": [
    ...
  ],
  "production_countries": [
    {
      "iso_3166_1": "BE",
      "name": "Belgium"
    },
    {
      "iso_3166_1": "FR",
      "name": "France"
    }
  ],
  "release_date": "2014-02-26",
  "revenue": 0,
  "runtime": 107,
  "spoken_languages": [
    ...
  ],
  "status": "Released",
  "tagline": "",
  "title": "Supercondriaque",
  "video": false,
  "vote_average": 5.6,
  "vote_count": 270
}

Not for me:

curl https://api.themoviedb.org/3/movie/248507?api_key=###&language=fr

and part of response:

"overview":"Romain Faubert is a 39 year old, single, medical photographer... and a raging hypochondriac. His doctor and only friend Dr. Dimitri Zvenka thinks he knows the cure for Romain: dating! But with the arrival of freedom fighter Anton Miroslav, everyone might get more then they bargained for..."

OK, my curl command just needed some quotes to include the "&" correctly - sorry.

curl "https://api.themoviedb.org/3/movie/248507?api_key=###&language=fr"

is OK

No problem, happy to hear you figured it out.