html links not working (using base href)

You have to quote attribute values with " (QUOTATION MARK) or ' (APOSTROPHE), not “ (LEFT DOUBLE QUOTATION MARK) and ” (RIGHT DOUBLE QUOTATION MARK).

This type of error is typically caused by writing code using a word processor (such as Microsoft Word or Apple Pages) with automatic replacement of quotes with typographic quotes (aka Smart Quotes) enabled. Try using a text editor (such as Visual Studio Code, Sublime Text, Komodo Edit, Emacs, or Vim) instead.

The other common cause for this error is copy/pasting code from a website where the author has let a WordProcess CMS or similar mangle their input in the same way as a word processor. Check code you are copy/pasting carefully.