Forum, I am currently writing my thesis in LyX and am writing a number of equations, many of which use greek letters. All has been working fine until today when I needed to use the greek letter “phi”. When trying to use that letter I get “could not find LaTeX command for character “phi” (code point 0x3d5). I am using the latest LyX on OSX with MacTeX. In the description of the error it says "Some characters of your document are probably not representable in the chosen encoding. Changing the document encoding to utf8 could help.” I tried changing my encoding to utf8 but it just breaks the document even more and doesn’t like the other greek letters. Any advice on how to get around this?