Status 500 - Internal Server Error when trying to get Access token

Hi Guys,

Not sure what the issue is but I keep getting this vague message "Status 500 - Internal Server error" when trying to generate an access token.

For some reason it doesn't reach "https://secure.au1.echosign.com/ " - I am in Australia.

I am passing the parameters below:

parameters.Add("response_type", "code");

parameters.Add("client_id", client_id);

parameters.Add("client_secret", client_secret);

parameters.Add("redirect_uri", redirect_uri);

parameters.Add("scope", "user_login:self");

Can someone reach out to me? Any help would be really appreciated!