Viewer replace characters with square

GroupDocs.Viewer Product Family
1

Hello,
we have a new bug. Viewer is replacing some characters and double characters in the document with an empty square. Can you take a look at it? They are not special characters.

We are using version 25.2.

Thanks, Jan

original_doc.pdf (2.4 MB)

incorrect_characters.png (24.8 KB)

2

@biczdim

Could you please provide more details about the specific characters that are being replaced with squares and any additional context regarding the document format or content?

3

Can you look at the attachments?

4

@biczdim

Looking at the screenshot I can see that double character (ligature) was rendered as an box.

Unfortunately, I have failed to reproduce the issue on Windows and Linux (Docker) with this
sample-app.zip (2.2 MB).

Can you please modify the application if the code differs from the one you’re using and share more information about your environment?

5

Hi @biczdim

I’ve also tried to reproduce your issue on my local PC with Windows 10 22H2, and also unsuccessful. I tried to convert your document to HTML with default options and output HTML files have no reported issues with squares instead of “ti” ligature. I’m attaching here a HTML file “Petr-licensed-page2.html” in 7z archive, which was generated by the GroupDocs.Viewer and it is Okay, please open it on your machine and check whether it is displayed correct in your browser or not.

I definitely see the squares instead of “ti” ligature when I open the “Petr-licensed-page2.html” in pure text editor like Notepad or in browser debugger. In particular, the word “bezpečnosti” in HTML markup is present as “bezpečnosꢁ”. But this text span belongs to the SPAN element, which uses a font “FSFDMB+Calibri” throgh the class-selector. And only if I disable this font in the browser debugger (or just delete the font content from the STYLE section in HTML markup), then I see the square instead of “ti”.

Hope this will help. If you are able to see the correct “ti” ligature on your PC when opening the “Petr-licensed-page2.html” in a web-browser, then please share your code for rendering PDF to HTML.

Waiting for your reply.

With best regards,
Denis Gvardionov

Petr-licensed-page2.7z (49.2 KB)
Ligature-ti-debugger.png (61.0 KB)