How to get there
This dialog box opens automatically if a legacy Finale file contains a
What it does
The Mirror tool has been removed from this version of Finale. If a file is opened that contains a mirror, you are prompted to convert existing mirrors to regular notes and rests. If you choose not to convert, you are able to delete the mirror but not edit it. To convert a mirror at a later time, select the region and choose Utilities > Check Notation > Convert Mirrors.