Well, this took me a while to figure out, disabling plugins and themes and such. . .
If you turn on selectable avatars enabled, but don’t have any selectable avatars defined, when you try to change your avatar, you get a modal that doesn’t let you do anything. Perhaps don’t allow enabling the feature before they have added avatars to select?
I think this is a 
. If selectable avatars are enabled and you log in with github, your github avatar comes in, allowing users to choose their own avatar (which I thought wasn’t supposed to happen with this feature).
Also, if allow uploaded avatars is disabled, it seems that one can still create an avatar via github. I don’t know if that’s intended.
meet 
?