Xcode displaying false code error messages ('Expected expression' and others)
Even though you can't see any weird characters on the screenshots (or in person) where the error is, there's actually a 'DLE' control code at the end of the line (see image):



I copied the suspect text to another text editor where I discovered the control character.  I do not know how this character got there as I've been typing code and not copy/pasting from the web or other sources.

Deleting the semicolon and everything after it all the way to the new line fixed the problem.  This and other invisible control characters really should be visible when 'view invisibles' are turned on.