Today my site had some mind-boggling problems that came seemingly out of nowhere (white screen of death, 403 errors), which then seemed to resolve themselves all on their own.
My site is mostly all recovered, back up and running as usual. But I am missing chunks of the WP admin panel. The 'updates' page is gone. The 'editor' option is missing under 'appearance'. The new plugin button is missing and I also cannot delete any plugins.
I tried replacing the files in wp-admin and wp-includes but I'm getting a lot of errors. It's really as if the site has a mind of its own right now. Any suggestions would be greatly appreciated.