If you have an on prem server and you’ve checked the box you should check the following:

1) log on to the server and check if the binaries are in the running dir of html2pdf inside a folder called binaries.

2) if they are not you can republish the espace so the binaries are written there. Check again and If they are still not there you need to analize the logs on servicecenter and possible on the eventviewer of the server to see what errors may be ocurring during the copy procedure.

3) if they are there you should run wkhtmltopdf from the command line to see if it is able to generate the pdf on your server.

for further clarification you can also refer to:

https://www.outsystems.com/forums/discussion/36044/the-system-cannot-find-the-file-specified/

Let me know how it went so I can try to understand what the problem may be.

Regards,

Jitendra