Hi Michael,
I have used the following code to get the urlToDsigner
string userAuthenticationToken = eslClient.AuthenticationTokenService.CreateUserAuthenticationToken();
AuthenticationClient authenticationClient = new AuthenticationClient("https://sandbox.esignlive.com");
string urlToDesigner = authenticationClient.BuildRedirectToDesignerForUserAuthenticationToken(userAuthenticationToken, packageId);
When i enter the url: https://sandbox.esignlive.com/auth?authenticationToken=ZGJhYmYzODktNzRiYy00YWI2LWJlMDYtYWVjNjg5ZGE3YWIw&target=https%3a%2f%2fsandbox.esignlive.com%2fdesigner%2fVwT5l