Ive watched many a BluRay and couple of  4K discs on X800 and it only froze up on me once.  I guess I got lucky. The only thing that p?ssed me off with this player is when the app stopped working that looked up CD information and displayed it on the screen. Not a biggy but I got used to it and liked and now its gone. 

 No wonder I like the blues so much 
