As I said, when I hit that "diagnostics tool" link in the above message, nothing worked in the tool. When I hit "soft reset" and read the directions, I used my IP address and the :8081 and that got me to the tool where it asked for the MAC address. After that, the diagnostic tool links worked. After the soft reset, the database restore did the trick.
Same here, on ups and also just working fine. My last system startup before this db corruption was August 11th. I'm on 2.2.7.128 though since that was working.
That message simply means: Your browser is retaining expired Credentials (MAC address). For most, clicking Log Out often does the trick, but some stubborn browsers refuse to give up. Try another browser, clear History/Cache to force the browser to ask for that MAC address again.