I got "Unable to authorize access because the client configuration is invalid: invalid_request"

I have OAuth problem : Unable to authorize access because the client configuration is invalid: invalid_request

I am trying to get the OAuth token on :

https://secure.echosign.com/public/oauth?redirect_uri=https://salesmgmt.cogitocentral.com&
response_type=code&client_id=J55Yxw9GB5YDz8MN1UjJkTvLJVqgbAGK&scope=user_login:self+agreement_send:account

[PII removed by mod]

Redirect uri is set the same as it is set in the API application settings. I tried in the browser. Result: 'Unable to authorize access because the client configuration is invalid: invalid