Reverting to Install Pages

Using the latest version of WordPress (4.0) on all blogs I manage, I found one where the page had reverted to the install page. All files were intact and all content was intact in the db. I went through the install process, copying and pasting directly from my wp-config, and the site came right back up.

As a precautionary measure I did a db repair and optimize, but the fact that it came back up suggests there may be something else going on.

I’m not using a lot of superfluous plugins (Akismet, Dropdown Menu Widget, Form Builder, iframe, Limit Login Attempts and Wordfence Security) and have a very simple theme (twentytwelve through twentythirteen and MH Magazine lite), all of which are up to date.

I’d chalk it up to a fluke except I’m starting to see this in my customers’ accounts as well. I directly own five sites, but work where I see and support hundreds of WP sites over the course of a month. When I start seeing an issue repeat with similar results, it sends up a red flag. This is more a heads-up than anything else at this point.

I didn’t see anything I could recognize as a hack, though I’m not ruling out that possibility. Maybe an exploit? I’d appreciate anything I could hunt for that might account for it, because I already know I’m going to start seeing more of these if this is any indication, and I’d like to know the fix (if there is one)