Blocked by Private encryption key?

We received this pop up message when trying to review older footage via the playback tab of the app. The events are still available. We haven’t set up a private key and don’t even know how to do that. The continuous footage is less than 30 days old. When it’s been overwritten, it gives a different message. I’ve never seen this message before. Newer footage doesn’t have this pop-up. Can anyone shed some light on this?

Here’s the photo of the error. The error popped up for 7 days of footage. The footage before and after aren’t prompting for a private key.