Moodle Version: Moodle 3.3.1 (Build: 20170710)
Database: MSSQL Server
Web Server: Windows Server 2016 Datacenter (Amazon AWS hosting?)

I am unable to backup my course. Clicking Backup always results in a Server Error: 

500 - Internal server error.

I have debugging turned on at the Developer level, but I am not getting any errors logged to help me track down the cause.

I have checked that all of the plugins (both default and additional) are up to date (clicking the Check for Updates button doesn't identify any plugins that need to be updated).

I have not made any changes to the core and changes to my existing plugins is strictly limited to layout and style changes; namely commenting out items on the display I would rather my users didn't see that I couldn't remove through settings within the UI.

I'm totally stuck and need to backup my base course so that I can duplicate it several times with minor changes depending on the intended audience as opposed to manually copying every change and update I make to the course five times.

What else can I provide to get this issue resolved?