You must be using TextEdit on a Mac. It is not possible that the suggested NotePad (the canonical plain text editor on Windows) would have shown that particular error. TextEdit assumes you want to add formatting to a text, and so it saves new files by default in the RTF (“rich text file”) format, but a script needs to be ASCII text only. That’s why it chokes on the very first formatting codes.
Make sure that you set TextEdit to “Make Plain Text” before saving.
Or, just use Adobe’s own ExtendScript Toolkit editor. It has the additional advantage that you can see syntax highlighting, so you’ll know it when a string is not properly defined.
By the way: your font is not named “Minion Pro.otf” – look in your Font menu! Just use the font name. If you want to add a style as well, you can add it after a tab after the font name:
var fonts = [ "Minion ProRegular", "Minion ProBold" ...