This was the second time I received this error message when trying to click on a motion event. Ironically this particular motion event should have been a “person detected” event as it was my daughter walking and getting into the car.
Try visiting Ring.com via web browser and logging in to play the video recording from there. As long as your Protect Plan subscription is in place and has not recently lapsed, a captured event should play. I recommend also waiting some time for the video to become available, and also considering mobile device variables such as connection or disabling a VPN.