Troubleshooting
The handful of things that actually go wrong.
Common problems
The scan says a folder is restricted
macOS has not granted access to it. Select the folder, choose Grant Access, and pick that exact folder in the panel. Some system folders cannot be granted at all. See why macOS asks.
The total is smaller than I expected
Restricted folders are not counted, because DiskPeek cannot read them. The status bar tells you how many were skipped. Snapshots and purgeable space also sit outside what any app can measure.
The scan slowed down in the middle
Usually dense directories or a slower region of the disk, not the app struggling. DiskPeek never reads file contents, so file size has nothing to do with it. Try Automatic before a higher performance profile, since more concurrency can make contention worse.
A saved favourite disappeared
Selecting it will offer to remove the stale entry. That only forgets the shortcut, it never deletes anything from your disk.
Deleted something but got less space back
Almost always APFS clones or a Time Machine local snapshot still holding the blocks. See on disk vs logical size.