Pay Pal Bad request Error

Invalid Http rsponse The remote server returned an error : (400) bad request.

Dictionary configurationMap = new Dictionary(); configurationMap.Add("mode", "sandbox"); APIContext apiContext = new APIContext(); apiContext.Config = configurationMap; CreateFromAuthorizationCodeParameters param = new CreateFromAuthorizationCodeParameters(); param.setClientId("My ClientID goes here");
param.setClientSecret("My Client Secert goes here");
param.SetCode(code); // Authorization code goes here
Tokeninfo info = Tokeninfo.CreateFromAuthorizationCode(apiContext, param);

GetUserInfor(info);