What are CID Fonts?
Today’s headache: a corrupted legal brief from a defunct law firm. Every time he opened the file, the text vanished, replaced by a cold, clinical error message: "Missing Resource: CID Font F1, F2, F3." cid font f1 f2 f3 free download link
CID Font F1, F2, and F3 are three distinct fonts that belong to the CID font family. Each font has its unique characteristics, making them suitable for various design applications. What are CID Fonts
Search for the "Adobe Acrobat Reader DC Font Pack (Continuous)". Link: github
Here is an interesting review of the situation, explaining why people look for them, the technical reality, and the safe way to handle them.
github.com/adobe-fontssource-han-sans, source-han-serif, source-han-monoOTC/ directory → SourceHanSans.ttc (Single file contains all CJK regions).