Hello. I have had a Roku device connected to my small Samsung TV for years and I rarely have had problems, although I had to replace the device already once as it was no longer working, and I could not watch any channels at all.
Lately, I have had the same thing you are describing happen to me but with my Amazon Prime account telling me to free up space etc.
Firstly, I do not know where to find "settings" after pushing my home button. I do not have settings on my screen.
After trying a couple of times to reset the device as suggested, pushing the reset button, even though the button was not marked "reset" on my device, I was successful in hearing some noises coming out of the remote, so something was happening. I tried again opening Prime but the same error message appeared. At this point I unplugged the device, waited, and plugged it in again, and it worked! The old trick of pulling the plug...came through for me this time. I can open the Prime App!
Try it!
