Make sure you have SteamVR running before you open Unity. That seems like it caused issues like that for me. If you still have issues you might want to shut down Unity and SteamVR then try it again. I’ve had plenty of times where certain models wouldn’t appear either and Unity would give an error even though it worked previously. The Steam plugin is still a work in progress so expect things like that but in general I find restarting things helps.
