This is a very strange issue. I just uninstalled Toolbox from my laptop and reinstalled it, and it seems to work there again without a problem, but on my desktop it's still not working. I'll finish up the remaining models (they only need wheel markers and hitboxes) and then transfer all of the toolbox files to my laptop, and then compile everything there. My content pack will be done soon, but this is a weird issue. It must have something to do with Windows or something. I'm glad I have a new laptop or I'd not be able to work around this. Yet another reason to be upset with Microsoft lol.
Tried that, but still no go :/ I'm working around it though. I basically moved my modeling over to my laptop, and I'm doing configs and such on the desktop (because typing is easier and all that). It's a nuisance but my pack is getting finished this week come hell or high water, lol.