This happens to me about every hour or so for a couple days now. It only happens sometimes when I start a test server.
When I start a testing server, this message would popup and closes all my Studio processes, the screenshot was a split second before it closed. Luckily I got a habit of saving every time before starting a test but it’s quite frustrating because I have to re-open studio and re-publish.
It would also sometimes say I’m not logged into studio when I run a test server but all I had to do when just re-run the test server.