Open the problematic PDF in a browser (like Chrome or Safari). Choose .

There is no single "CID Font F1" file because F1 is just a label for whatever font the original author used—often common fonts like , Myriad Pro , or Helvetica . Downloading a random file named "CID Font" from the internet is unlikely to fix your specific PDF and may pose a security risk. Instead, you can fix the issue using the following methods: How to Fix Missing CID Fonts in a PDF

: Included with Creative Cloud subscriptions and designed to work seamlessly with Acrobat.

When a PDF is exported with "subsetting" enabled, the software might assign generic names like F1, F2, or F3 to different weights or styles (e.g., F1 for Bold, F2 for Regular).

: Offers high-quality, free-for-commercial-use fonts. How to repair a PDF file and embed missing fonts

Understanding and Fixing CID Font F1, F2, F3, F4, F5, F6, F7 Errors