Originally Posted by kiwidude
The plugin will now better handle the situation of Goodreads having broken image links on their website and correctly return no url to Calibre rather than an invalid one.
Thanks, I suspect the reason why it popped up so often when I tried it was because Amazon cover lookup wasn't working so it tried to pull all covers with your plugin instead of just what it couldn't find on Amazon, this greatly increase the chance of hitting these.
I check that URL you gave and it's clearly Goodreads and/or AmazonS3 fault, they're sending back HTTP/1.1 OK, the only indication that it's bogus is the zero length, nasty. I have to thank you for solving that issue, several of your plugins are immensely useful.