3D...

[Llian]

Don't recall doing this before but now I have to select all each time I add an element; and only then everything is shown on 3D. Am I missing something? 

[John Stanford]

I don't really remember from which option / menus you'll have access to this command but:

1. try to open your 3D window
2. press F5 (or fn+F5)
3. double check layer combination & layer visibility settings