I feel silly asking -- given how old IE9 is, but it was working yesterday, and now it's not.
I upgraded from 7.7.9 to 7.7.10 and today users get either a blank white page, or a blank white page with the "helpful" missive "error on page" in the status bar.
I didn't see support for IE9 ending listed in the release notes, so I'm hoping this wasn't intended.
Anyone have a fix or workaround?