PdfCreator on Apache/php - windows server

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 2.5

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