YouTube API - The API Key and the authentication credential are from different projects

Question

I am trying to get videos from youtube with my C# application, with "https://youtube.googleapis.com/youtube/v3/search?forMine=true&order=date&type=video&part=snippet&key={key}&access_token={token}" but I receive this error:

"error": {
    "code": 400,
    "message": "The API Key and the authentication credential are from different 
projects.",
    "errors": [
      {
        "message": "The API Key and the authentication credential are from 
different projects.",
        "domain": "global",
        "reason": "badRequest"
      }
    ],
    "status": "INVALID_ARGUMENT",
    "details": [
      {
        "@type": "type.googleapis.com/google.rpc.Help",
        "links": [
          {
            "description": "Google developer console API key",
            "url": 
"https://console.developers.google.com/project/{MyProjectCode}/apiui/credential"
          }
        ]
      },
      {
        "@type": "type.googleapis.com/google.rpc.ErrorInfo",
        "reason": "CONSUMER_INVALID",
        "domain": "googleapis.com",
        "metadata": {
          "consumer": "projects/{MyProjectCode}",
          "service": "youtube.googleapis.com"
        }
      }
    ]
  }

But I can see only 1 API Key and 1 OAuth 2.0 Client ID (with Client ID and Client Secret) on https://console.cloud.google.com/apis/api/youtube.googleapis.com/credentials?authuser=1&project={MyProject} site

Could you please help how can I fix this ?

Code:

var token = Helper.Decrypt(ytConn.AccessToken);
var url = "https://youtube.googleapis.com/youtube/v3/search? 
forMine=true&order=date&type=video&part=snippet&key=" + _key + 
"&access_token=" + token;

videos = Helper.GetFromAPI<Videos>(url, token);

it calls this:

public static T GetFromAPI<T>(string url, string token)
{            
    WebRequest request = WebRequest.Create(url);
    request.Method = "GET";

    ServicePointManager.SecurityProtocol = 
    SecurityProtocolType.Tls12;
    request.Headers.Set("Authorization", "Bearer " + token);                

    request.ContentType = "application/json; charset=utf-8";

    T type = default(T);

    try
    {
        using (WebResponse response = request.GetResponse())
        {
            using (Stream dataStream = response.GetResponseStream())
            {
                using (StreamReader reader = new 
                StreamReader(dataStream))
                {
                    string responseFromServer = reader.ReadToEnd();
                    type = JsonConvert.DeserializeObject<T> 
                    (responseFromServer);
                }
            }
        }
    }
}

Thanks in advance

Answer 1

There was no need to change the code, on one day started working again, so most probably the issue was on Youtube side.