For the last year or so, I've been using this link to display my combined flair
As of yesterday (?) that image link is broken and redirects to https://stackexchange.com/error?aspxerrorpath=/users/flair/1144664.png.
My Stack Overflow flair still works - https://stackoverflow.com/users/flair/1127699.png
I can see that other people's Combined Flair still works e.g. http://stackexchange.com/users/flair/1.png
According to the Flair page, my link is correct - so what's going on?