I’m about to rip what little hair I have remaining over this, so If somebody knows the solution then please step forward!
I use a native.showWebPopUp to display local PDFs for reading offline. This works fine when they’re downloaded. However, when the user first starts the program I want them to be able to view a “getting started” pdf that is located within the ResourceDirectory.
It doesn’t work 
Does anybody have any ideas why?
If you need me to put anything up, just ask 