Windows – setting up PHP 5.6.3 to work with IIS 8 on Windows Server 2012

First time asking a question so please bear with me. I don't spend a lot of time using IIS but decided to dip a toe in the pond. I have a server that is no longer in production but is still good enough so I thought I would turn it into a ticketing server. I wanted a free ticketing system that has the ability to pull from LDAP. I read good things about OSTicket so I thought I would give it a whirl.

I have IIS 8 working with PHP 7.1.1 nts x64, php manager, and MySQL 5.7 on this windows 2012 server. I was able to create the new site and was able to load the new site and get through the basic config but then I can't log in to the system. I read some posts that indicate that OSTicket 1.10 doesn't yet work with PHP 7.1.1 and that downgrading to 5.6.3 is the solution. I then attempted to install php 5.6.3 but can't get it to work (I get 500 errors). I've installed both the x86 stable version and the x64 experimental version. Same issue with both. Rebooting hasn't helped. Stopping and starting the site hasn't helped. Can anyone help me understand what might be wrong? Here are the basics of what I did to get it setup:

For x86 version:
I created the folder C:\Program Files (x86)\PHP\v5.6
I copied the contents of the PHP installer into that folder
I copied php.ini-production to php.ini
I added the path to the path system variable
In IIS I added the application to the FastCGI settings to match the one for 7.1.1
In IIS I added the module mapping to match the one for 7.1.1

when I use PHP Manager in IIS to change to 5.6.3 and then tell it to check phpinfo() I get the 500 error whereas when set to 7.1.1 no error and I get the phpinfo printout. Any assistance would be greatly appreciated. Thanks!

EDIT: Here is the log output:

• System

  • Provider

  [ Name] Application Error

  • EventID 1000

  [ Qualifiers] 0
  Level 2
  Task 100
  Keywords 0x80000000000000

  • TimeCreated

  [ SystemTime] 2017-02-13T14:53:42.000000000Z
  EventRecordID 15667
  Channel Application
  Computer SAS2K10.sands.lan
  Security

• EventData

  php-cgi.exe
  5.6.30.0 58803748 MSVCR110.dll
  6.2.9200.21941 5792e533 c0000135 000683ba cd4 01d28608f81651f3 C:\Program Files (x86)\PHP\v5.6\php-cgi.exe
  MSVCR110.dll 35d5e51a-f1fc-11e6-93ee-984be16edd6e