You cannot transfer coins directly from old PAC wallet to new $PAC wallet. You need to use the updated version of the old wallet, so called Redemption wallet:
https://image.prntscr.com/image/lMgaTCiFRqOp-Cs_jisPDw.png
in order to send coins to the redemption address. Here are the instructions:
https://paccoin.net/wp-content/uploads/2018/01/Fork_Redemption_Guide.pdf
https://www.youtube.com/watch?v=sFHmX58reB8

Also, read recent posts in this topic.