Posting this on behalf of someone in one of my leagues...
"PLEASE help! It's been a couple years since I've had a team, and I dont remember this issue anytime before. My team is $19M over the salary cap. Another owner has proposed 3 trades that would put me below the cap, but I can't accept them because each one would still leave me over the cap so it cancels the trade. Is there a way around this?"
If all three trades together are going to bring your team under the cap, maybe try putting all the pieces (players/draft picks) into one mega-trade, that way it's all in one big one and you save two trades with that team for later on in the season if you choose to do any more trading.
We tried that and it still didn't work. My team is currently $19,973,049 over the salary cap. The trade that we have on the table would get rid of $24,327,346 and I would get $1,133,119, so that should put me well below the cap, but it still won't let the trade go through.
Could try offloading the salary in one trade, and then receiving the incoming salary. Involves a bit of trust I would think. Still new and haven't made a trade so I'm not speaking from experience.