FPDF session variables - mysql

Question

I have a web application that I've built on Wordpress version 4.1.1, I'm using PHP 5.4.22 and MySQL 5.5.42-cll.
The application collects user entry via form input fields, through a series of 4 consecutive pages, and stores to session variables. On the last page, there is a print to PDF feature that displays the customized PDF for user download. This PDF is generated via FPDF.
I had this feature working and am not sure what change, or auto-update in wordpress could've caused this to stop working. But I have troubleshot and narrowed the problem down to this:
The session variables aren't making it to the FPDF PHP files. I'm able to verify that the session variables remain on the page prior by printing them to the page. Again, I didn't change any of the code in the FPDF files or data input pages.
Please help if you can. I'm not certain what the problem may be.
Additional Info:
Around the same time this error was found, I was working on forcing SSL throughout wordpress. I ended up using the plugin WordPress Force HTTPS. I speculated this could've over-wrote something, but I'm not sure. The code within this plugin is simply:
function toz_force_https () {
if ( !is_ssl() ) {
wp_redirect('https://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'], 301 );
exit();
}
}
add_action ( 'template_redirect', 'toz_force_https', 1 );
Any assistance would be greatly appreciated!

Answer 1

I found the answer. Please forgive my oversight, this may be a super simple answer but I'm posting it so someone else doesn't go through the same frustration.
All of my session variables were stored on
https://www.example.com
and I was launching my FPDF via
https://example.com
I learned the hard way that Session variables in PHP are lost when changing the domain. Hope this saves someone some time.