Ok, so the summary here is the URL's on cdimage don't have anything after 20101020ubuntu318. So 20101020ubuntu318.15 doesn't exist on cdimage. It's odd they are still publishing builds like that, with an extra dot. This isn't really something the tracker can handle.
Best bet is to ping in #ubuntu-release and see if someone who has access can edit the script that posts these builds.
Ok, so the summary here is the URL's on cdimage don't have anything after 20101020ubuntu318. So 20101020ubuntu3 18.15 doesn't exist on cdimage. It's odd they are still publishing builds like that, with an extra dot. This isn't really something the tracker can handle.
Best bet is to ping in #ubuntu-release and see if someone who has access can edit the script that posts these builds.