Most of the time, the "download" you need is the Adobe Acrobat Reader DC Font Pack .
However, to help you (or others who search this term) get useful results without risking malware from sketchy "hot download" sites, here is you can use for a blog post, forum reply, or search guidance.
generated by PDF software (like Adobe Acrobat) when a font was not properly embedded in the original file. What is CIDFont+F4? A Software Substitute
Open the PDF in Chrome or Edge. Modern browsers have very robust built-in PDF engines that are often better at "guessing" what a missing CID font should look like than older desktop software. Conclusion
