A problem has come up which wasn't there before - when I try to edit a post or page, the big content editor box where the content of the page normally shows up, is blank.
When I inspect the content edtor with Firebug (in Firefox), I note that the text is there in the HTML, but that it is not visible in the browser.
I have tried de/re-activating and updating my plugins, and have updated to the latest version of WordPress, but to no avail.
Has anybody had any experience of this problem, or an idea of what might be causing it?
Any suggestions or help would be very gratefully received.