A search for a class in the fulltext search on the top right of the Javadoc results in a 404. For example, a search for "MongoClient" takes you to the page: http://mongodb.github.io/mongo-java-driver/3.11/javadoc/undefined/com/mongodb/MongoClient.html.

It's not clear where the "undefined" is coming from. The URL should just be: http://mongodb.github.io/mongo-java-driver/3.11/javadoc/com/mongodb/MongoClient.html