Hitachi smart tv problem


Hello. So I have a hitachi smart tv 32 inch for about a year now and so far it worked perfect. Yesterday I tried launching the YouTube app via the red button which gives access to these apps but a Grey screen pops up that says "An unexpected error has occurred, please try again later". Why is this happening and what can I do? Netflix works via the separate button in the remote and I can launch YouTube only from connecting from my phone? What can I do? Thanks