If you just need to print or display the graphics correctly without editing the text itself: Open Adobe Acrobat Pro. Go to > Print Production > Preflight .
If you are receiving an error that "CIDFont+F1 cannot be found," try these solutions instead of downloading unknown files: How to fix font issue to make PDF file show properly? cid font f1 f2 f3 f4 f5 f6 f7 fonts free download work
They are because they are arbitrary labels. What users actually want is the original base font (e.g., Source Han Sans, Noto CJK, Microsoft YaHei) or to extract the embedded subset . If you just need to print or display