Hello, thanks for getting back to me!
I'm currently using version 1.2. I haven't modified the code. It does work perfectly fine when I drop it into a new project and proceeds through the demo as expected.
That's good to know! Unfortunately it does mean that it's interacting with something in your project then, which I can't debug. Note that shaders can interact with each other in odd ways sometimes, in case that gives you an idea of where to look. If you find any more information, let me know in case there are compatibility changes I can make!