I'm trying to get some examples to learn about MC Add-ons Programming. However, the package of official turned-based RPG demo (package version 0.0.7, offered on the minecraft.gamepedia.com, an example of Custom HTML UI) doesn't work. When I loaded the .mcworld file offered and entered the world, it properly displayed two buttons through Custom HTML UI, but the right game process just couldn't go on. After I pressed either of the buttons, nothing happened.

I tried to look through the code of this demo and made some tests. I built a new resource&behavior pack to test Custom HTML UI, it appears that onClick events in custom .html file can't be triggered, but mouseover events can (other events yet haven't been tested on my PC). When I pointed to the element, it runs my script as ordered (like changing the innerHTML).

Moreover, the minecraft:unload_ui event may well not be able to properly triggered. I tried to change the required event of the RPG demo from click to mouseover, but still, nothing happened.

Is my steps wrong? Or is it a particular error only with my computer? Is there any methods to get rid of this frastrating occasion? Please reply, thx!

Below here's the captured image of the start interface of the RPG demo reffered to.