Issue with Downloading Converted PDF File (403 Error) - Certificate Verification Problem

Greetings community,

I am currently facing a problem while attempting to download a PDF file that was converted from a DOCX using the OnlyOffice Conversion API. Every time I try to download the file, I encounter a 403 error. Upon examining the logs, I came across the following error message:

":UNABLE_TO_VERIFY_LEAF_SIGNATURE;connect:undefined Error: unable to verify the first certificate."

In my search for a solution, I stumbled upon this forum thread: Download failed... 403 forbidden - #3 by FelixFuernhammer, which addresses the exact same issue. I followed the suggestions mentioned in the thread, and as a result, I no longer have any logs related to the error. However, despite these efforts, the problem still persists.

I would greatly appreciate any insights or suggestions that could help resolve this issue.

Thank you in advance for your support and expertise.

1 Like

Hello @djibril

Please let us know version and installation type of Document Server. Also, describe how the conversion request is sent and the response that you receive for better understanding.

Hello @Constantine

Thank you for responding to my message. Here is the information you requested:

Version: 7.3.0
Installation type: ONLYOFFICE Docs Developer Edition

Regarding the way the conversion request is sent and the response I receive, I have provided a screenshot .

To download it via link in the browser please try next:

  1. Copy the link and paste it to the search bar;
  2. Remove amp; but leave the & sign from the link (POSTMAN highlights these pieces);
  3. Press Enter to download the file.

Here is an example of the link:

…/cache/files/data/conv_pdf/output.pdf/Document.pdf?md5=N_8j8U5mo28Wtp7ujWdLAg& expires=1689591812& filename=Document.pdf

After removal of amp;:


Hope it helps.


Yes, it works! Thank you!

1 Like

Glad to hear it!

I had the same issue , It works thanks!. But why amp is used in link?

As far as I know, this is how ampersand (&) symbol is encoded and it results in being replaced with &.