Troubleshooting & messages · Moving, offloading and restoring apps
What does "Storage Studio couldn't determine how this app is updated" mean?
Short answer: Storage Studio couldn't tell how this app updates, so it can't promise updates will work after a move. You can still move it — if an update fails, move it back, update, and move again.
Before moving an app, Storage Studio looks at how it updates itself — through the App Store, its own updater, or an installer — because some update methods don't follow an app to an external drive. For this app it couldn't tell, so it can't promise updates will keep working after the move.
You can still move it. If the app later fails to update, move it back, update it, then move it again. See moving apps.