from a browser to see if it flattens the fonts into shapes. To help you resolve this more quickly, could you tell me: What language is the document written in? What software gave you the error message?
When a PDF is created, the creator should embed the fonts into the file. If they forget, your PDF reader will try to find the font on your local machine. If it cannot find it, it substitutes it, often causing an error or displaying scrambled text. Cid Font F1 F2 F3 Free Download
Yes, the underlying CID-keyed font technology is designed to be OS-independent, and web browsers using modern font formats (WOFF/WOFF2) and operating systems with proper language support handle them well. However, the specific placeholder name issue is a PDF rendering problem, not a font compatibility problem. from a browser to see if it flattens the fonts into shapes