CID fonts, including F1 through F7, are crucial in:
Here is what is actually happening and how you can fix your document. What are CID Fonts (F1, F2, F3...)? cid font f1 f2 f3 f4 f5 f6 f7 fonts free download link
The following links point to officially redistributable versions of CID-keyed fonts or open-source equivalents. Always respect font licensing. For personal or educational use, these are safe. CID fonts, including F1 through F7, are crucial
Understanding the "CID Font F1-F7" Error: Why You Can’t Just Download Them including F1 through F7