This is a bizarre edge case, that I suspect has to do with something particular to this site, but I don’t know where to look.
One user, joe-admin, an admin, sees a “handle membership request” link on all PMs. It’s a link to
/g/everyone/filter=joe-admin. The link doesn’t work, because everyone isn’t a group.
I have a plugin that allows everyone to send PMs to staff. I’d think that this was the cause, but I’m also an admin and I don’t see those links on my messages.
Any hints on where I might look for an explanation would be appreciated.