Trailers mostly unwatchable

I seem to have a bit of a problem watching Trailers. Some previous builds back, I was able to view online trailers (trailers from the Internet) before some Plex server and Player upgrades. It usually played perfect without too much buffer either on 2Mbps (720p) or 1.5Mbps (480p) but now even putting it on the lowest setting possible, heave no results. At first I thought it would be my Internet, but that does not seem to be the problem as either streaming sites like YouTube and Crunchyroll, I can play full HD without any issues. Even playing trailers on IMDB and HD-Trailers.net plays fine at 720p. Is there a possibility to increase the buffer or add a offline trailer folder feature as it is a nice feature to have before watching a movie.