How to fix this error code on a 4k Firestick
If you are running a VPN on your Fire TV or Fire Stick, temporarily turn off the "autoconnect"/ "connect at boot/start-up" feature in your VPN and reboot your device.
Make sure you can play any Prime video again without getting the error, and then turn back on the "connect at boot/start-up" feature in your VPN.
Once again confirm you are still able to play Prime video content.
There is also this procedure for devices not running a VPN:
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