If anyone can help me PLEASE

Is it possible to copy rosters from season after a fantasy draft, and then used to start a new career in my player mode, PLEASE HELP

Yes, but only with a Player/Full license of REDitor

with the full version of the REDitor you could try selecting all of the data in the teams tab and copying it from the association/season to a my player save

Where can I find a full version?

releases forum, it lays out the options for you, no guarantees it will work though for what you want

JaoSming, If you have the Player/Full version couldn't you just open the Association file and then save it as a normal roster?

EDIT: just tried it, without success just get a message that it is corrupted

i really dont know, i dont want to spend time trying to get this to work because you have to go back through and add your my player ID and i dont know how that works.