引用自 Ismokehellaweed：

Im trade banned and i dont know why

i tried trading with one of my friends and its not letting me send any trades and now its saying im trade banned but not for what i was wondering if anyone could help me or knew anything about why i would be banned out of no where

You just changed your profile name...

https://psteamcommunity.yuanyoumao.com/profiles/76561198953851134/namehistory

You won't find any official documentation about it.

The unfortunate part about the new profile name change trading cooldown (4 hour cooldown every time you change your profile name) is that page (linked below) will only state, "we have confirmed your account is unable to trade" generic message. Leaving people wondering wtf is going on.

https://psteamhelp.yuanyoumao.com/en/wizard/HelpWhyCantITrade

The error while you trade during this cooldown is error (34).

It took a while earlier last year to figure out Valve silently added the new cooldown.

https://psteamcommunity.yuanyoumao.com/discussions/forum/1/4202490424033360096/

Just an FYI the name change trading cooldown is mostly due to the fact that most people dont frequently change their name. And there is also an extremely high correlation between a hijacked account and a change in profile name.