This is a weird one. I was editing an asset field on a Craft install that's been working fine for weeks. When I went to save the asset I got a little read snackbar message at the top of the Craft page saying "server error". Then all of the sudden the page reloads to
/admin/install with the big red Install Craft button in the middle of the screen.
I cannot access any admin pages now - they all redirect to the install page. But the site's front-end is still working - Craft is still serving all my content just fine.
Craft is obviously still installed, but something has gone wrong to make it think it's not.
Where do I start to debug what happened here and how to get it back up and running?
Would it be dangerous to click that Install Craft button (would I lose any of my data or otherwise mess up the current install)?
Is there a config file I can update to fix this?
I'm running Craft 184.108.40.206 according to the composer.json file.