This seems to have surfaced when trying to open an Mbin magazine from Connect (via Lemmy of course), by tapping on them in the subs list (or searching/tapping).

If I search for !teletext@fedia.io or !FloatingIsFun@fedia.io they both give this error, so I think it's something to do with Mbin magazines. I haven't seen it happen on Lemmy communities.

Hopefully tapping those links will show the error - they do here.