callAPIMethod:withParameters:success:failure: Request failed: unauthorized (401)

[ghost]

I wrote an app that allowed the user to search for a song in Rdio. I'm calling the API method called "search" and everything was working fine. However today I tried the same code (without any changes at all) and now I'm getting the following error:

Error Domain=com.alamofire.error.serialization.response Code=-1011 "Request failed: unauthorized (401)" UserInfo={com.alamofire.serialization.response.error.response=<NSHTTPURLResponse: 0x12e5afd70> { URL: https://services.rdio.com/api/1/search } { status code: 401, headers {
    "Access-Control-Allow-Origin" = "*";
    "Access-Control-Expose-Headers" = "x-rdio-api-version";
    "Cache-Control" = "no-cache";
    Connection = "keep-alive";
    "Content-Language" = "es-mx";
    "Content-Length" = 82;
    "Content-Type" = "application/json";
    Date = "Fri, 25 Sep 2015 19:00:43 GMT";
    P3P = "CP=\"This is not a P3P policy. See http://www.rdio.com/legal/privacy-policy for more info.\"";
    Server = "nginx/1.2.4";
    Vary = "Accept-Language, Cookie";
    "X-Version" = 720;
    "X-srv" = "srv-108-16";
} }, NSErrorFailingURLKey=https://services.rdio.com/api/1/search, com.alamofire.serialization.response.error.data=<7b226572 726f725f 64657363 72697074 696f6e22 3a202249 6e76616c 6964206f 72206578 70697265 64206163 63657373 20746f6b 656e222c 20226572 726f7222 3a202269 6e76616c 69645f74 6f6b656e 227d>, NSLocalizedDescription=Request failed: unauthorized (401)}

If I translate the error response data I get the following:
{"error_description": "Invalid or expired access token", "error": "invalid_token"}

I don't understand why I'm getting this error if, according to the documentation, this API method "Does not require user authentication."

[dasevilla]

All API methods require an access token. There are two types of access tokens: with or without a user. For methods labeled "Does not require user authentication" you can use the Client Credentials Grant to generate an access token without a user.

Once you've generated an access token it will expire within 12-hours. After it has expired, you need to use a refresh token or use the Client Credentials Grant to generate a new access token.

[Pugintv]

@dasevilla Will this work with the new SDK update released?