Gui not responding Colorslide tutorial

I was following the colorslide tutorial on Defold.com. I could not get the GUI buttons working. I used print statements too but nothing comes in the console logs. I went through a thread on similar problem on defold forum but I could not understand the problem.

Please help.

https://drive.google.com/open?id=1wlnJVP6f0LAx9mIE_-DfVIRLKzqAyRCW