On https://docs.mongodb.com/manual/tutorial/install-mongodb-on-os-x/ (and potentially other pages) it assumes that the URL and filename for MongoDB 3.6 is https://fastdl.mongodb.org/osx-ssl/mongodb-osx-ssl-x86_64-3.6.0.tgz.

This has changed to https://fastdl.mongodb.org/osx/mongodb-osx-ssl-x86_64-3.6.0.tgz.

The change to remove "-ssl" will continue moving forward (per anonymous.user).

This affects not only the curl command on this page, but also the cp command a few lines down.