Parts of PDF text are not displayed - like whiteout has been wiped across

Which product are you using?

PDF.js Express Version

Detailed description of issue
Really odd issue, which I expect is not caused by pdfjs-express-viewer however I’m hoping that people on this forum may have encountered it before.

In short, a small number of Windows 10 / Chrome users have reported that when they view SOME of our PDFs, using pdfjs-express-viewer have this rather strange display issue:

Updating OS, Browser and Graphics Drivers have had no effect, neither has enabling/disabling Hardware Acceleration.

Users tell us that the “whiteout” disappears if they “zoom in a lot” (to the point where they can’t read it without a lot of scrolling).

Microsoft Windows 10 Pro 10.0.19044
Google Chrome 103.0.5060.134
NVIDIA(R) GeForce(R) MX330 with 2GB GDDR5 graphics memory

Expected behaviour

Text displays normally.

Does your issue happen with every document, or just one?
SOME PDFs, not all.

Link to document

Code snippet
N/A (I think)

Whilst no errors appear in Chrome, the issue persists in Edge, and this message appears:

 TT: undefined function: 32 pdf.worker.js

Any ideas would be really appreciated.

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Hello nickmyersdt,

This is similar issue that we have seen, see this community post on how to work around it: Choppy text rendered with Windows and Chrome - FAQ - PDFTron Community
it also has more information regarding the issue.

Best regards,
Tyler Gordon
Web Development Support Engineer

1 Like

Thank you Tyler! That looks identical, we’ll make a note of that and give the workaround a go ourselves.

You have saved me from endless trawling of search results trying to describe the visual effect accurately!