Nostalrius Begins - Quality wow vanilla realm (1.12)

Hello!
About 30 min ago i try to farm rich thorium at Silitus. I was killed by horde and log out. After this send 50 gold to my bank account and start monitoring auction. After ~20 min i try to enter my main account and get message that it "is closed and no available to use". Account name - Mandor.
Why my account si closed? I didnt do any forbidden actions.

dear Mandor ; your account has been permanently banned for abuse of an ingame bug.

Krusher wrote:dear Mandor ; your account has been permanently banned for abuse of an ingame bug.

May i ask what kind of bug i was banned for?