Recently it seems as if there are a lot of new users without an avatar.
First I thought it was just a plain white picture, but as this happens more and more often, and also sometimes those users get highlighted as recent posters in the overview with just a very small grey-ish circle in the upper left corner of the list of avatars of a thread, I assume that there has to be a bug with the default avatar generation.
Last active poster: You can see an example of the “small grey-ish circle” in the third and last thread of the screenshot.
Seemingly no conversation at all: In the fourth thread it seems as if there were noone to post or to answer, that particular thread though has 2 replies at the time of this writing: How to read error messages?
In the first thread of that screenshot, you can see that my own avatar is slightly off to the right compared to the avatar below. In that thread there also was such a ghost-poster.
I noticed that when I click to know who liked my post sometimes people appear without their avatar. It just shows " liked it". Strangely, I can see the avatar of this person in the same thread …