Cidfont-f1 F2 - F3 F4 F5 F6 !!top!!

Some fonts—particularly commercial typefaces with restrictive licenses—cannot legally be embedded in PDFs. In these cases, PDF creation software may substitute CIDFont placeholders as a legally compliant workaround, even though it renders the text uneditable and non-selectable.

CID fonts are designed to handle complex languages that use large character sets, such as Chinese, Japanese, and Korean (CJK). Unlike Western languages that use a few dozen letters, Asian languages require thousands of unique glyphs. Cidfont-f1 F2 F3 F4 F5 F6

If you have Acrobat Pro, you can force the document to fix itself: CIDFont+F1 issue - Adobe Community such as Chinese