The keys were stolen by a ten-foot chicken. We chased him for hours; finally, in a blind alley, we cornered him and, with the help of a mysterious Colonel in white, we wrested the keys from him.
<serious mode>Well, the truth is that a minor edit to improve functionality led to a major glitch with an error hiding somewhere like a lurking termite - and that major glitch meant that the forum threw a number of errors, rendering it inaccessible. We've been working on it all day, and we're inexpressibly relieved that finally, finally, finally the problem was narrowed down.
Because we'd performed a forum backup before the edit, we were able to restore the forum to the point just before things went pear-shaped.
I'm now going to give myself some of the mango and passionfruit swirl icecream which I bought in expectation of our finally fixing the problem.