PDF document text disappearing

[Tara5FBA]

After downloading a pdf and editing it (highlights and comments) I tried to save the document and it wouldn't but also when trying to save the actual document text ALL disappeared, leaving only highlights and comments behind (i.e. blank paper) I have a macbook pro (mid-2012) with the most updated catalina

[Bevi Chagnon - PubCom.com]

Could be that the fonts were not embedded into the PDF at the time that it was created by the original author.

Best solution:

Go back to the original source document (not the PDF) and re-export it, choosing the option to embed all fonts. You should then be able to edit the PDF without losing the text.

But it would make more sense to make your editorial changes in the original source document and re-export a new PDF that doesn't need editing at all!

Next best solution:

In Acrobat, open the original PDF and select the Preflight Tool Panel (right hand side). Drill down to the section to Embed Fonts. You can view instructions here: Use Acrobat to Embed Fonts Into PDF. 

If the PDF used commonly available fonts, there's a good chance this will work. If it used fonts that you don't have on your computer system, then all bets are off.

Bottom line: All PDFs, at the time they are made from the source document, must have the fonts embedded.