400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Munimenta+Gildhallæ+Londoniensis:+Translation+Anglo-Norman+passages+Liber+albus;+glossaries;+appendices;+index+john+carpenter because the request was invalid.

This might be because the link was created a long time ago. Try your search again on Google. That’s all we know.