Sometimes opening the PDF in a different viewer (like macOS Preview) and using "Export as PDF" can re-encode the file and fix the font mapping. Safe & Legal Font Downloads
When a PDF is generated, the creator can choose to "embed" the fonts inside the file. If they choose not to embed them, your PDF reader must look for that exact font on your local operating system. Because "CID Font F2" is a temporary name unique to the creator's system, your computer will not find it. 2. Corrupted Font Cache
通过本指南，你已不再是遇到问题时的被动搜索者，而是成为了一个能够解析字体根源并采取有效行动的知识型用户。当PDF中的 CIDFont+F2 再次出现时，你将知道：那只是一个等待被优雅替换的占位符，而你已经拥有了解决它的完整工具箱。 Sometimes opening the PDF in a different viewer
The error most frequently occurs when a PDF is saved with broken font subsetting. The document knows it needs the glyphs associated with "Font F2," but the actual font data was left behind or stripped during a file compression process. 3. Font Substitution Failures
Go to > Preferences (Windows) or Acrobat > Preferences (Mac). Select the Page Display category on the left. Uncheck the box that says Use local fonts . Because "CID Font F2" is a temporary name
If you open a document created by someone else and your system does not have the original typeface, your PDF reader will try to substitute it. If the fallback font mapping fails, the system throws the generic "CID Font F2 Normal" error. The Risks of Random Online Font Downloads
Did you , or did someone send it to you? The document knows it needs the glyphs associated
Professional users can use the Preflight tool in Acrobat Pro to convert TrueType fonts to CID fonts, which can resolve "Invalid CIDTOGID Map" errors. Downloading from OnlineWebFonts.com
Alternatively, you can also try other online font repositories, such as Font Squirrel or DaFont, which may also offer the CID font F2 normal for free download.