CRM 2011: Console app to CRM - The Provided URI did not return Service Endpoints

Hi Folks

I have a console app which tries to connect to my live CRM 2011 on premise instance and returns the below error.

System.InvalidOperationException:

Data[0] = "The provided uri did not return any Service Endpoints! {0}" Data[1] = ""

I have referred to the below post and done all the checks but no luck yet.

- Restarting CRM Asynchronous Processing Service

- Recycling CRM App pool from IIS Manager

- Doing a IIS reset

http://alagunellaikumar.blogspot.co.uk/2016/06/the-provided-uri-did-not-return-any.html

https://community.dynamics.com/crm/b/mahenderpal/archive/2013/09/19/the-provided-uri-did-not-return-any-service-endpoints-error-ms-crm-2011-quick-tip

Note: This app works fine in our test servers.

Could you give me some advice please?

Thanks

AB