🚀 go-pugleaf

Do you have Times installed and active on your computer? If you do, and you have made sure that you do not have CG Times specified anywhere in your FM docs, then you should have no problems. 

It sounds to me like you have been using the printer's Times font for your FM styles and your preferences are set not to remember missing font names. Thus, when you change printers, you change to one with CG Times installed instead of Times and the fonts are substituted. You then save and when you change back to the original printer, your CG Times fonts are no longer there and you get the missing fonts message. That's just a guess, but it fits the situation you have outlined. 

So, to summarise, never use printer fonts - always use fonts resident on your computer - and/or don't save the file when you have changed your printer or you are opening the file on another computer unless you have chosen to remember missing fonts or you are happy with the font substitutions. 

Dominic