I did some more research and someone suggested that perhaps you have Windows Defender's "controlled folder access" enabled. Here is the link they mentioned: https://docs.microsoft.com/en-us/windows/security/threat-protection/microsoft-defender-atp/enable-controlled-folders
Apparently there's a means of whitelisting programs, or you could otherwise just entirely disable the feature. I don't know for sure what would be good practice for yourself because my computer habits are surely different than yours and anyone else's, so it's your choice if you wish to disable such a feature. That being said, you seem relatively savvy and I would think that you would be perfectly fine with the feature disabled, because I am sure it would be preventing many other 3rd party programs from functioning properly that you might wish to download and use. PixelCNC isn't doing anything out of the ordinary when it comes to reading/writing files, it's pretty much bog-standard routine stuff for programs going all the way back to the Windows 95 era.
It'd be a great help if you could confirm whether or not this is the issue. Thanks!
Charlie