docusign integration with asp.net mvc

Question

Error calling CreateEnvelope: {
 "errorCode": "USER_AUTHENTICATION_FAILED",
 "message": "One or both of Username and Password are invalid."
}

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: DocuSign.eSign.Client.ApiException: Error calling CreateEnvelope: {
 "errorCode": "USER_AUTHENTICATION_FAILED",
 "message": "One or both of Username and Password are invalid."
}