OfficeToPDF not executing via shell_exec

问题

I am executing the command in by localhost on the command line as:

OfficeToPDF.exe C:\wamp\www\editor\uploaded\uploaded_files_21_original\AffidavitinDIR-4.docx C:\wamp\www\editor\uploaded\uploaded_files_21_original\pdf\new2.pdf

This runs fine and provides the necessary result.

However, when I run it through php as:

shell_exec('OfficeToPDF.exe C:\wamp\www\editor\uploaded\uploaded_files_21_original\AffidavitinDIR-4.docx C:\wamp\www\editor\uploaded\uploaded_files_21_original\pdf\new2.pdf');

It does not execute and throws an error as:

Object reference not set to an instance of an object. Did not convert

I have been searching for all possible solutions but no luck. I am running this on my windows machine - Localhost WAMP.

Any help please!

来源：https://stackoverflow.com/questions/24241164/officetopdf-not-executing-via-shell-exec