Why does Snap! not execute my script?

I have a button, with this script.
it doesnt work

But when I execute this, the button doesn't work.
So I tried this:
it works
Okay. Now I know, that the boolean reports true.

When we put out the boolean script and set the input to true, we get this:
this works
Now the button does it's stuff. Why?

Can I see the full script?

You will find the script at the bottom of the long script in "BaumenĂ¼".
~Deleted Project~
Sorry, it's German, so I don't know, how much of the script you will understand.
Just click on the script, to execute it, then press "Los geht's", then press "weiter" in the dropdown-menu, and then try to press "Erledigt!" in the dropdown-menu. Because there is nothing scripted after this, the script should stop itself after a short time.

Unless that IF is inside a FOREVER, my guess is that the mouse isn't down (yet) at that point in the script.