Unable to activate latest Katalon studio Testing tool

I planned to use Katalon (Free) with Jenkins.

After populating all the headless scripts for several testing over past 3 months I decided to go live on our production servers.

I registered with a new user email id and password and I'm able to login with the credentials here: https://www.katalon.com/sign-in/

However, after downloading the latest katalon from here:

Once downloaded and extracted; I'm unable to use the software with the same credentials i used above to login. I get Unautorized message when trying to Activate the tool.

Note: I do not wish to used the licensed (paid) version but the free version that used to work before.

I was a little concerned reading this thread with the similar issue.

https://forum.katalon.com/t/question-is-katalon-studio-still-free/32780/6

Can you please suggest if I downloaded the incorrect setup, or if, I m missing something activating the tool or if Katalon has actually tricked us into believing this was free which it is no more !! . If so any alternate free solution / tool to katalon ? Please suggest.