It's been a while since I selected Trailers in the Movie, Information (context menu) option. Today when selecting the Trailer icon, I got a dialog to Add-on YouTube. Then the Installation fails. Tried from the repository, and it failed too. How do I view trailers via this icon in the Information? I can view Trailers with IMDB Add-on, but I like the convenience when selecting the Movie, then using Information from the context menu (simple from my remote control).

hi, try to install this zip via addon. then try again.

click

Movie trailers requires the YouTube addon.  You should be able to install it from the link that @acid303 provided.  I've had times where add-ons won't install, and then later on it will work.  

Not that this matters, but this instance of trailers for the movies doesn't have anything directly related to PreShow.