Glass Material: Raytracing Translucency?

No matter what I do. As soon as I fully Raytrace the Refraction / Transluceny … the Glass Material turns out to be black.

Here is a short 4k-Video that describes very clear the problem:

Please, don’t spam your questions on every section. The moderators will move the threads to the correct section if they see it has a better chance at being answered there. I just answered one of your posts and showed up another two exactly same posts. Most people use the “New Topics” link at the top of the page and it brings new created threads from all sections.