(Finale 25 on Windows 10 - totally useless to this question) When we change key signatures in Finale, it seems we have only two options, selectable in the Document>DocumentOptions>KeySignature dial...
I had to copy an entire score from a Finale 2007 document to Finale 25 (Win10), and everything worked well except the percussion line, which was all messed up. I had to use Utilities > Transpose Pe...