We've confirmed that your account, weihai12, is currently unable to participate in trading.
You are on a trading cooldown because you cancelled trades that were pending or in a trade hold.
Once you accept a trade offer it is important to let it complete and to only cancel if you realize you have been trade scammed or deceived in some way. Cancelling trades just because you've changed your mind or because you don't want to wait for the trade hold makes it hard for others to have confidence in trade offers.
Cooldowns for cancelling accepted trades last for 7 days.
This restriction will expire in 6 days, 18 hours and 27 minutes.
Steam Support is unable to remove or change the duration of your cooldown.