If you recently upgraded to the latest version of ChemDraw and/or the latest version of MacOS (Big Sur or Monterrey), you may be prompted with a warning that says that Times New Roman (or Times) will be replaced with the Helvetica font when opening old ChemDraw documents.
Recent versions of MacOS include an updated version of the Times font that replaces Times New Roman. Sometimes Times New Roman is also included, but it is an updated version. Also third party applications you install can make this change.
If the original font used is changed or not even present, you will receive this error on documents that include that font.
To resolve this problem, restore the fonts on your computer by going to the Font Book app on your Mac, choose File > Restore Standard Fonts.
If that does not work, simply go to google and look to download again the fonts (Times and Times New Roman) and install them again on your OS.