Troubleshooting & messages · Moves and copies that didn't finish
Why does it say an app keeps its files in a private area, so Storage Studio won't move it?
Short answer: The folder belongs to an app that can only read its data from its own protected area; a shortcut would make the data look missing. Use the app's own storage setting instead.
Some apps — especially those from the Mac App Store — are only allowed to look for their data in their own protected area. A shortcut pointing elsewhere stops them finding it, so the app would behave as if its data were gone. Storage Studio refuses these moves to protect the app.
If you need the space, look for the app's own setting to store its library or downloads elsewhere, or clear its cache if it's offered.