If you see an icon like this. It means the environment needs to be downloaded before you can start using it.
To download hover over the button. You will now see a bar with a title, description and a button for download. Click on the download button. A pop-up will appear, where you can choose if you want to download, download and switch or cancel.
If you choose "download" it will be downloaded and you can see it with a green checkmark in your list. If you choose "download and switch", the environment will be added to the list as well as to the active scene.
The active environment will always be at the top of the list.
If you remove an environment you will see the standard void with the grid as you see in the second image.
