I was having the same problem. You need to transfer FF to the same PSN account. I had a different PSN on my 4. I made a second user on my ps4 and used the PSN email and password from the 3. Make sure you save the 2nd user. Then logged onto the 4 in the second user and clicked on FF. It loaded fine. I did not need the code. You finally get to the data center select screen. Then you watch the first scene again, it finally leaves you on your character screen. Good luck, hope this helped.