Troubleshooting & messages · Free space and clean-up messages
Why won't Storage Studio tick some files for me because it can't tell which app they belong to?
Short answer: Storage Studio only pre-selects what it's sure of; it can't tell which app these belong to, so they're left unticked. Look inside in Finder and tick them yourself if you're sure.
Storage Studio pre-selects only what it's sure about. For these files it couldn't tell which app they belong to, so it can't be confident removing them is harmless — they're listed but left unticked.
Open them in Finder and look before choosing. If you're sure you don't need them, tick them yourself.