How do I force TextEdit to not add .txt extension (Sierra) I have TextEdit default to plain text files. I also have "Add .txt extension to plain text files" unchecked in the "Preferences" in the "Open and Save" section.

If I perform these steps:


Create new document
Write some text
Click on title bar to set the filename and save it
Type foobar.md in the "Name" box
Hit "Enter"


The result is that the file is actually named foobar.md.txt.

How can I get TextEdit to actually not add .txt to file names? And what is the point of that box in "Preferences" if it doesn't actually do anything?
Don't use the name in the title bar to change or set the file name. Use the file menu option save, or hold the option key and select save as.  This lets you chose your extension name. I encountered a similar problem using title bar to name the file.