Some antivirus programs, such as AVG or Avast, may block applications from doing file operations such as deleting files and folders, moving or copying files and folders, dragging-and-dropping files and folders, importing files, saving files, etc.

If you are using AVG or Avast, within the anti-virus program, please go to Menu | Settings, and select Blocked & Allowed Apps.Select ALLOW APP, and then add your ACDSee program to the list.

This should remove the restrictions on your file operations.