Go through your CREATED PLAYERS and any player that is a Free Agent, click the triangle to delete them. Eveytime you install/update a team that has a CREATED PLAYER, you need to do this as when you install the team, it creates another version of the player tied to the team and releases the prevous player to Free Agent. If you don't, you end up with duplicates.
Thank you, that partly solves my problems.
Any advice on how I can get Roy Keane, Makelele, Baggio and other former players away from Master League? I do not tick of the box "include classic players" when I'm starting a new ML. I can also not delete those players in edit mode.