Win10/Win8 - Apps won't run ("Another Instance" + "Requires Windows _ or Later")

This is probably due to special work environments, but I thought I'd check with you folks.

I work in a public school system and I've always used PortableApps to keep a handy drive full of utilities for my job. Everything worked fine until I came back to school last month...

We transitioned MOST computers to Win10 last year. Everything was fine, however when I try to run the platform OR any individual portable app now:

1) I generally get a "Another instance of ______ is starting. Please wait for it to start before launching it again." I get this error when starting up the platform as well, but the platform actually runs -- it's just that any launched portable app doesn't.

or

2) "[Software] requires Windows or later. This PC is running Windows ?, so [Software] can not be started." (Yes, it has a blank and a ? in the error.)

If I go into each app's directory and run the original file in App>AppName> , it works. The portable versions don't, though. This happens on both the Win8 and the Win10 computers...

Is there anything that can be done about this? I'm assuming it's tied to some sort of weird issue with the custom security settings, but I can install the full versions fine, and I can run the executables inside the portableapp subdirectories, so I'm a bit confused...