I think the problem is that in the original code it is intended that when a user clicks a button he then has a dialogue asking for input. When the user sends that message lfs sends out an insim packet called "IS_BTT", 'Button type'.
Now if you go and remove the byte in the Send_BTN_CreateButton method call that tells lfs to create a button that when clicked produces an input dialogue, lfs creates a plain clickable button and when clicking a simple button like that you receive an insim packet called IS_BTC, 'Button click' in response.
TL;DR your code is never triggered because the packet receiving action is never called because you are expecting the wrong type of a packet.