Yep, I'm having the same issue?? Not sure how to fix.
I've tried using different computers and still have the same issue. Also have tried logging into different accounts. I assume this is a SuperCoach problem???
I've found a small away around but most likely not worth doing.If you hit the save team button it will erase your entire team which allows you to play around for the meantime. But once you hit save team again your team will lock then you'll have the same issue when trying to trade players in and out. Hopefully they fix this asap, not long left until the first game.
Mine working fine atm.