Editorial Comments window has disappeared

I’ve been using Edit Flow, mainly for the editorial comment feature, for about a month. Some time this afternoon, the Editorial Comments window disappeared across the site. I cannot figure out what happened. No admins were signed in (except me, when I logged in and discovered it gone) although other editors were using it. I got a notification about an editorial comment an hour or so ago, but now the comment (and all comments, site-wide) are gone, as are the windows for making comments.)

I checked and the Editorial Comments have not bene disabled.

Any advice?

https://ww.wp.xz.cn/plugins/edit-flow/