PdfCreator on Apache/php

I have an application that runs on Apache server and uses Pdfcreator COM interface to generate reports in pdf format.

the scenario before:

windows server
Apache 2.0
Php 5.1
PdfCreator from version 1.7 to 2.5
All worked correctly, the reports where generated, stored and sent via email

the current scenario:

windows server
Apache 2.4
Php 7.1
PdfCreator 3.2

when I run my app via the php passthru() function, then the command
::oPdfQueue:WaitForJobs(nDocs,nTimer) goes into timeout, the report sent to the PDFCreator printer is not captured and no pdf file is created

I tried with php exec() and shell_exec() instead of passthru() with no results

if I run the application from ‘outside’ Apache, from the windows desktop it works fine and the output is captured and the pdf file is created

I also tried to install PdfCreator in the same directory of Apache server with same results

Can anyone help?
thank you

Hi Roberto,
have you find solution meanwhile?
I have almost same scenario, desktop application works PDFCreator with COM interface.
If use same approach in my web app on Apache, it do not create and catch timeout on PDFCreatorQueue.WaitForJob(5)

Sorry but no 'clean' solution here.
The only way to make it work has been to run Apache from a batch file in automatic startup rather than as a service. It seems that in this way it has admin privileges to correctly execute pdfcreator.
Hope it helps

I see. so problem lies in admin privileges of it. Thanks