A17 error?

I was watching remotely tonight on my FS and all of a sudden everything froze so I backed out to my recording list and selected the content I was watching and all I got was an error A17 screen. Same happened on other recordings and live TV.

Not sure what happened, but rebooted the FS and when I came back later everything seemed fine. weird. What is A17?

What is FS? Details are important to give accurate answers. What hardware are you using? Which software versions? What do the logs say?

Fire Stick. Log shows no unusual activity, recordings firing as they should.