I wouldn’t start rotating keys just yet. This is an Operator Site, I think the first thing to do is to check whether the operator still exists. A fairly common issue is for one or more clients to fail to unsubscribe from an operator that has been deleted - they keep trying to gather an opsite that no longer exists.
I’m away from computers now, but should be able to help later this weekend or early next week with some session relevance to check whether the site is even still valid.
In shorts it’s an annoying error message but usually can safely be ignored, especially for an opsite