Red signs in Cubase

Hello! I am on Learning Cubase. Although I have experience in FL Studio and Ableton Live a couple of years, I am trying to learn Cubase. But this waste my huge time due to repeated sound missing problem. particularly in Cubase Artist Program. Some parts are very interesting though. I am downloading optional products/items, most of them are not working and rather giving some red signs . Are we have to buy them seperately ?

I have watched many youtube videos, here due to absence of control room the problems cant be solved by me.

Hi and welcome to the forum,

Where did you download the content from, please? If you select Cubase version_number Artist in the Steinberg Download Assistant, you will get a list of content, you have a license for (which is part of your Cubase license. Download all from here and nothing more, please.

What problem exactly do you face, please?