Build something that works
The process for setting up the 'subl .' shortcut is different depending on what operating system you're using. You'll be able to find some helpful troubleshooting information in the comment threads below either the 'Installation for Mac Users' or the 'Installation for Non-Mac Users' videos.
If you need troubleshooting help in the future, just post a comment in those threads, as this will give me more context on how to best help you. The Ask a Developer forum is best for general questions unrelated to any of our courses. Thanks!