Janusz, I provided the information you gave me to the server support team, can you please advise on any steps I can now do to troubleshoot based on the following response from them:
"I reviewed the script and I noticed that the fopen and fwrite PHP function are used.
I created a test script in the same location which is working properly. You can check it bellow:
http://freedombrew.us/frontaccounting/reporting/includes/test/test.php
The information is added in the file bellow:
http://freedombrew.us/frontaccounting/reporting/includes/test/data.txt
You can also go to the URL below, delete the content in the data.txt file then visit the script and it will be added again.
https://cp.freehostia.com/filemanager/#/www/freedombrew.us/frontaccounting/reporting/includes/test
As I was able to understand the script is trying to access a file named "doc.pdf" which doesn't exit in the directory where the script is located, however this information might not be accurate because we are not familiar with this script and your developers is supposed to troubleshoot it.
I'm afraid that we can not proceed troubleshooting the case because the used function are working properly as you can see which indicates the the problem is not caused by the directory permission or any other server configuration."
I can provide you access to my server if you need to see anything directly for more clarity but this is beginning to frustrate me as I can't figure out for the life of me why it is not making these reports.