Selection assistant not working

[cvierow]

I just upgraded to version 4 and ran a scan. It came up with several duplicates. I tried using Selection Assistant to mark all but one file in each group, but nothing is getting marked. I also tried manually checking each file I want to delete. Again...nothing. Why isn't it working? Also, my screen is messed up. Please help!

[DigitalVolcano]

Did you set an input folder as 'Protected' in the folders to scan section? You can't mark protected folders.

What's wrong with the screen?