Hi Dave,
They were never there? I just added mine as favorites from my D:drive. from my older version of Sketchup. Even if I copy that folder to the User/AppData...folder it still does the same.

Glyn

Hi, I have upgraded new desktop and Sketchup and I am having trouble with thumbnails showing in the styles window.
I keep all my components off the drive to save clogging so saved Styles, Materials and components on and set them all as favorites for file location.
I'm running Windows 10 and Sketchup 2015pro, any ideas?