We upgraded to latest MyBB
Are you getting any errors on this support forum?
I'm not personally getting the errors at all on either forum. At least, I haven't yet. It does seem to be random. At the moment, it seems to be just 4 posters but they are my most active users so, if it is random, they are the most likely to get hit with it just because there's more opportunity for it to happen.
Ok, if happens again find what type of device/browser
I don't think it's happening at posting time because I found some examples that were first posted over ten years ago. We would surely have noticed it before. The most recent one I found was posted two days ago.
When did the update happen?
I know that the characters are appearing on a wide range of browsers on the display side. I'm still waiting to find out what was used to post them.
Hah! One just appeared in my sig. line
Speaking of which, why is my sig. line only appearing on some posts?
Updated just happened in last two days.
This looks like a core MyBB bug