How to port M16 rosters to M15 & vice versa:
Needs:
Xbox 360 formatted flash drive
Madden 15 roster
Madden 16 roster
Programs:
Xanathol's Madden Roster Editor V1
Modio
HxD
Microsoft Excel
1. Create 2 folders, label them default and edit. Add a M16 roster to the edit folder and the same M15 roster to both folders. Both the M15 and M16 rosters must have the same number of players
2. Open the M16 roster with Xan's editor and export all players using the Action Tab, All Players, Export. Name the CSV roster file it creates and save. Now open the CSV file with Excel and copy the contents.
3. Open the "edit" M15 roster with Xan's editor. Export all players, name it and save. Now open excel again and paste the M16 CSV contents into the M15 CSV. Save the M15 csv.
4. Go back to the "edit" M15 roster with Xan's editor and import all players from the M15 CSV file. Save the roster.
5. Load the hex editing program HxD and open both the "default" M15 roster and the "edit" M15 roster. Copy and paste the entire second line of numbers of the "default" roster over the second line of numbers in the "edit" M15 roster. Now save.
6. Open Modio and drag the "edit" M15 roster onto a 360 formatted flash drive and save the roster to the flash drive.
M15 and M16 share the exact same CSV file structure when opened in Excel so they are easy to port. You can also import an individual player from one roster to the next using Xan's editor.
M13 and M25 share a file structure that is only 4 categories different than M15/M16 but I have not been able to port an entire roster from M15/M16 to M25 or earlier Madden's. I have only been able to import individual players after fixing those 4 categories. Click my username and go to a Legends roster thread I started that explains the differences. Should be a couple posts down in that thread. Check some of my posts in Xan's roster editor thread for further help. You'll probably have to search the forum to get specific answers to M25. I haven't ported a roster to anything other than M15 so I am not the most knowledgeable on earlier Maddens.
I think M11 and M12 share a file structure which is different than M13-M16 which would make porting to M11/M12 even more difficult. I did see a convertor file posted somewhere in this forum from a year or two ago when I was using the search words "Madden 12". I don't know anything about it so you're guess is as good as mine whether it works and how it works.
The Madden 2000's (I checked M07 anyway) have a completely different file structure than all the 2010's Maddens. These rosters are useless for importing players or even for game faces because it is so different. The 2000's and 2010's might as well be different games for editing purposes.