Invalid Characters

I am just getting started with FontCreator 14. I have loaded a .ttf font I made in 2004 with FontCreator 4.2.4 that has 47 glyphs. FontCreator 14 shows the message “Invalid Characters” but I can’t find an explanation why the glyphs are invalid. I attached a picture showing the message I am seeing. To update this font, I need to know what the problems are. How can I see why the fonts are invalid?
Invalid.png

The glyph names do not match the glyphs.

Cent, Sterling, Currency shoud be ¢ £ ¤

Try converting the Symbol font to Unicode from the Tools menu.