The PDF was watermarked for a certain period of time

Which product are you using?

PDF.js Express Version


Detailed description of issue
{Description here}

On April 15, 2024 at UTC, a watermark appeared on a PDF for an hour or two starting around 10:00 am.

I did nothing and after a while the PDF watermark disappeared.

Was the license server unstable?

Expected behaviour
{Provide a screenshot or description of the expected behaviour}

Does your issue happen with every document, or just one?
{Answer here}

every document

Link to document
{Provide a link to the document in question if possible}

Code snippet
{Provide a relevant code snippet}

Hi there,

Are you able to provide any network logs at the time? Can you see if any of the requests are failing?

Best Regards,

At the time, “” returned a 200 response, but the PDF had a watermark.

Currently, the PDF has no watermark and displays correctly.
Therefore, it is not logged.

I thought it was an effect of the license server as it resolved itself over time.
Could you please investigate if the server is the problem?

I can confirm the occurrence again and will post the log.


(index) Value
UI version ‘8.7.0’
Core version ‘8.7.4’
webviewer.min.js ‘8.7.4’
Build ‘Ni8xNi8yMDIzfDhhZjQyYTgwOTU=’
WebViewer Server false
Full API false



Status Code: 200 OK
{"key": "ÆÖÜýÍÚÈâÉüüÃÅüíêͺø÷×ãÖ÷¸"}

Hi there,

We have not found any server failures on our end.

You will need to create a rest API key. You are currently using your license key as your API key.

Please see this guide: PDF.js Express Utility API | Documentation

Best Regards,

Thanks for confirming.

Why do I need a REST API key?

Since the Utility API is not used, I think license key is fine.

Could you let us know what features you are currently using? Are you using Express Viewer or Plus?