If you can see the text but it looks distorted, or if you need to send the file to someone else without errors, you can "flatten" the fonts into vector shapes. Open the PDF in Apple's native app.
This guide breaks down exactly what this error means, why it happens, and how to resolve it safely without falling for malicious software downloads. What is CIDFont+F1? cidfont f1 font free download for mac extra quality
: When a program generates a PDF but fails to embed the actual font file, it assigns a generic label like "F1," "F2," or "F3" to the missing character set. If you can see the text but it
: Most fonts that "F1" might be standing in for (like Arial or Helvetica) are already installed on your Mac in /Library/Fonts/ . Managing Fonts on Mac If you do have a legitimate font file you need to install: Open the Font Book app from your Applications folder. Drag and drop your .ttf or .otf file into the window. Click Install to make it available to all your apps. CID+ Fonts - Adobe Community What is CIDFont+F1
If you want, I can:
Searching for a "free download extra quality" file for CidFont F1 is highly discouraged for several reasons:
Broad Compatibility: High-quality CID fonts follow strict OpenType or PostScript standards, preventing crashes in software like Adobe Illustrator or InDesign. How to Get CIDFont-F1 for Mac