Same problem here (Kauai, HI). I have spent hours on the phone and chat with Samsung and also with Amazon Tech support. Today I was on chat with Samsung and after going through the same shut down, start up, sign in again, yada yada and at the end of the session I was told that Samsung was going to issue a software update to the Amazon Prime Video app in the next two weeks. Anyone else heart this?
So I have been having a similar problem with the prime video app, however the screen either is completely gray and if I select whatever the cursor is on and that will play but it's a total shot in the dark or selecting the app only gets a flashing "prime video" logo and nothing less happens. Any suggestions?
Deregister Device AND (2) unplugging TV for 1 minute (+holding down on button for 20 seconds) worked for me too. Have to do this regularly for Amazon prime. Samsung should really sort this!! Very annoying.
Anyone with other suggestions? Prime has never loaded on my TV. Just goes back to the Smarthub. I have shut off and on, pushed the power button for 5, 25, and 30 seconds as listed in different posts, Reset the Smarthub, Looked for updates, the TV is not registered on Prime, as it has never been used for Prime, set DNS to 8888, unplugged TV for the night, plugged in, pushed power button, held power button, reset entire TV, tried to watch Prime through the internet app and cried a lot......