You just take the contents of “common” and paste them into the root of the font. For clrlst and mnum you can leave folders (as long as they are in the root of the font) or paste directly into root of font, they’re the same as other effects.
When you Edit Font, it will overwrite to “font;common”. This is built into Edit Mode.
To find the error(s) run ‘effects’ in Serial Monitor.
Remove DISABLE_DIAGNOSTIC_COMMANDS define and upload
Leave saber connected and go to Tools > Serial Monitor
Type ‘effects’ and it will list the sounds and any errors.