There is a (rather overzealous) filter on the commonly used [
easylist.to]
EasyList that looks like:
CODE
.org/ad/
Unfortunately this filter can trigger on some gallery thumbnails.
Assuming this is the issue and you're using something like uBlock Origin or AdBlock Plus, a possible workaround is to add an override of the form
CODE
@@||ehgt.org/ad/*$image
This will exempt gallery thumbnails from being blocked.