Duplicate files · Duplicate messages and problems
Why does it say "Pick which copy to keep first" or "At least one copy is always kept"?
Short answer: They're safety checks. Removal always keeps one copy, so select which copy stays with the round selector; Storage Studio never removes every copy of a file. To delete a file completely, remove the last copy yourself in Finder.
Both are safety checks. Removing duplicates always means keeping one copy, so Storage Studio needs to know which one stays — if none is selected you'll see "Pick which copy to keep first." Select one with the round selector and try again.
"At least one copy is always kept" appears if a removal would take every copy of a file. The Duplicates window never does that. If you really want a file gone entirely, delete the last copy yourself in Finder.