evgeny-alhovik5405 avatar image
evgeny-alhovik5405 asked John Wang commented

Cannot authorize with RingCentral C# Client

Cannot authorize via C# Client

sample code below:

rc = new RestClient(Config.Instance.appKey, Config.Instance.appSecret, false);

var result = rc.Authorize(Config.Instance.username, Config.Instance.extension, Config.Instance.password).Result;

The error is "Request to failed with status code 400 (Bad Request)."

In case I try to use C# SDK, I always get following response error:


"error" : "invalid_grant",

"error_description" : "Invalid resource owner credentials."


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1 Answer

Tyler Liu avatar image
Tyler Liu answered John Wang commented
Please check the password. The error message means your password is invalid.
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There are two types of accounts for development:

Production credentials - this is used for production use 

Sandbox (test) credentials - this is for the test environment

When you are accessing anything with "devtest" in the domain, you should use your Sandbox credentials which are provided in the Developer Portal under the Credentials tab as mentioned by Tyler

1 Like 1 ·
I just tried an invalid password and I got the same error message.
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Am I right to say that same password used to login to ? I can log in there with my password. Even I can send sms via  API Explorer 

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One more error message I get when I use C# Client 
  "error": "invalid_client",
  "errors": [
      "errorCode": "OAU-153",
      "message": "Invalid client: ",
      "parameters": [
          "parameterName": "client_id",
          "parameterValue": ""
  "error_description": "Invalid client: "
0 Likes 0 ·
There are two kinds of RingCentral apps: private and public.

Please double check. Is your app public or private? If it's private, only certain users can login. It might be the root cause of the problem.

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Developer sandbox tools

Using the RingCentral Phone for Desktop, you can dial or receive test calls, send and receive test SMS or Fax messages in your sandbox environment.

Download RingCentral Phone for Desktop:

Tip: switch to the "sandbox mode" before logging in the app:

  • On MacOS: press "fn + command + f2" keys
  • On Windows: press "Ctrl + F2" keys