I found the culprit, and it may have been.. TotalCommander! And me, obviously
There's an option in total commander that says 'hide system files'. If it's enabled, AND you start PureBasic from within TotalCommander, PureBasic itself still could find the application data folder, but any of my own programs could not. At least, that's what I think it was, as it's working now and I'm not planning to try again
