Adobe Reader Error: Cannot extract the embedded font '... Cambria'

[Intelligent2013]

Source: metanorma/mn-native-pdf#355 (comment)

If comment contains bold text, then Adobe Reader shows message

sometimes when tab 'Comment' automatically opens.

Found forum threads about this issue:

• https://answers.acrobatusers.com/I-Adobe-Reader-XI-facing-Cannot-extract-embedded-font-CAAAAA-LiberationSerif-error-open-q197198.aspx
• https://community.adobe.com/t5/acrobat-discussions/issue-with-embedded-font-cannot-extract-the-embedded-font/m-p/10581525
• https://community.adobe.com/t5/acrobat-reader-discussions/19-012-20036-introduced-cannot-extract-the-embedded-font-hnqflr-stonesanslt-identity-h-error/td-p/10574518
• https://community.adobe.com/t5/acrobat-discussions/embedded-font-error-opening-pdf/td-p/10571228
• https://community.adobe.com/t5/acrobat-discussions/quot-cannot-extract-the-embedded-font-quot-some-characters-may-not-display-or-print-correctly/td-p/10090976
• https://community.adobe.com/t5/acrobat-reader-discussions/quot-cannot-extract-the-embedded-font-quot-and-windows-10/m-p/12443670
• https://community.adobe.com/t5/acrobat-discussions/cannot-extract-the-embedded-font-error/m-p/4267101

To do: Acrobat Pro DC Preflight can show what the problem.

[Intelligent2013]

Sometimes Adobe Reader displays message about 'Cambria' font (non Bold):

[Intelligent2013]

Adobe Acrobat Reader DC Version 2022.001.20117

Adobe Acrobat Pro DC Version 2021.005.20048

Tools -> Print Production -> Preflight - no problems found:

[Intelligent2013]

The issue in the Adobe Reader, not it Apache FOP or PDFBox.
I've created a simple .docx in MSWord 2019: text.docx with using of two fonts - Cambria and Cambria Bold.
Note: this .docx doesn't contain a comments.

Then 'Save As' as PDF: text.pdf
When I open it in the Adobe Reader (currently, I'm using the latest version 2023.003.20244), and then click View->Tools->Comments->Open I get the error:

Sometimes (in 30% of cases), this error doesn't show.

I'll ask the question on Adobe Reader forum.
But the same 2 years ago issue https://community.adobe.com/t5/acrobat-reader-discussions/add-stamp-free-text-annotation-to-existing-document-inc-save-extract-embedded-font-warning-comment/td-p/11980066 without the solution so far.

[Intelligent2013]

Asked here: https://community.adobe.com/t5/acrobat-reader-discussions/cannot-extract-the-embedded-font-cambria-bold/m-p/13963494

[ronaldtse]

@Intelligent2013 do you know how Adobe Acrobat works with bold fonts in comments? Is it the font-embedding mechanism that differs, or the comment-encoding mechanism?

[Intelligent2013]

@ronaldtse Adobe Acrobat/Reader uses the user-defined system font for comments displaying, not embedded font:

The error occurs even when the PDF doesn't contain the comments (#124 (comment)).