Hello! I found that when you change the opacity of the button background image to zero (From the Image Blend Color settings), the button doesn’t work anymore after that. Of course its avoidable by removing the picture from the background and set the opacity to 1-255, but it could save hours of time not trying to figure out why the button isnt working 
Just wanted to point this out!
this is how it should be! A search on this forum will lead you to a description of why this is done!
This is normal behavior!
In order to make the button inactive, when it is not visible, it seems to be not there!
So, this is not a bug, but rather even a feature!
Yeah, i thought this too later on. But this was more about troubleshooting, not so much bug report. 
Would be nice to have somekind of “info bars” inside the app for like a noob like me, that doesn’t understand those kind of things at first. 
Then the application from technologically - professional, to turn into information and entertainment. I do not support. Moreover, you only need to figure it out once!
It’s like driving a car …
Imagine, you are driving, and you don’t know where the glass cleaner turns on, and then the glove compartment opens, and from there there is an informational sign))))) click on this button!
In general, there is a forum to help you, even experienced users may not know everything.