3 has uncovered some issues with the setup instructions, since a lot of time has passed and many new versions of components under the hood of this tool have been released.
The right version of RubyInstaller now resides on the separate "archives" page which is not very prominently featured
Bundler 2 has been released; and while it has taken great care to reinstall and run the right version, installing the right version from the get-go makes the installation simpler and ligher
3 has uncovered some issues with the setup instructions, since a lot of time has passed and many new versions of components under the hood of this tool have been released.