A similar thing happened to me. I had some domains with tons of backlinks hosted on app engine. Without any notice, my app engine version got deprecated and m

A similar thing happened to me. I had some domains with tons of backlinks hosted on app engine. Without any notice, my app engine version got deprecated and my sites went offline. I hadn’t setup any monitoring as I trusted google. I visited one of my sites manually and saw it was down. It turns out both of my sites had been down for two months. I logged into the google app engine ui to see an error message for both apps that I was running “a deprecated app engine version”. Most of the backlinks to the sites had been removed as broken links. Thousands of customer reviews of software I had published were erased by that. I dig google but this was an enormous failure on their part.