I just bought a 65” Sony Bravia 4K tv and was able to watch Hulu on it the first couple of days that I had it but now every time I open Hulu the screen will go grey and then back to the home screen. Same thing happens when I try to open puffin as well.
Have you plugged in a USB thumb drive and has the app been transferred to it? I have a USB drive plugged into my TV and moved some apps to it to see what would happen and the performance turned to shit.
The option is in settings/apps/ if you haven't plugged in a USB then this will not apply.
Had this happen on a customers Sony tv.
Did a full system reset. Reboot. Then apps started working again.
Clear the app cache