If the text looks fine but won't edit, try "printing" the file to a new PDF.
Common real fonts mapped to such internal names: cidfont f1normal font free download work
It was a typical Monday morning for Emily, a graphic designer at a small firm in the city. As she sipped her coffee and booted up her computer, she realized she had a looming deadline for a new project. The client had specified that the font used for the brochure had to be a very specific one: Cidfont F1Normal. If the text looks fine but won't edit,
Avoid third-party “CIDFont download” sites. Use Ghostscript or Noto Sans CJK to resolve the missing font issue legally and securely. The client had specified that the font used
If you are editing the file, manually change the font of the affected text to Times New Roman Cidfont+f1 Font Free - Google Groups