How in the world did you find that?
I noticed the issue last week when I wanted to do some updates to my system description. In recent months it has been evident that "remembering" log-ins has been erratic on the forum part of the site, so I figured the issue might have something to do with that. Therefore I suspected that performing a log-in on the forum part of the site immediately before clicking the "edit this system" link, but without leaving the page on which that link appears, might do the trick. Which suggested doing the log-in in a separate browser tab. Just took about 3 or 4 minutes for me to discover that.
BTW, I notice that there are now some writeups in the Audiogon blog about the revisions to the forum and virtual system software. Click on "Blog" under "Community" on the Audiogon home page.
Regards,
-- Al