With MT4, when we receive an error 149 (ERR_TRADE_HEDGE_PROHIBITED) or an error 150 (ERR_TRADE_PROHIBITED_BY_FIFO) from your broker, your account is automatically flagged as a "Netting" account. This means trades must be closed in First In, First Out order meaning trades must be closed in the order they were opened. To ensure smooth operation, Duplikium Trade Copier will automatically close positions beginning with the oldest open trade first without waiting for further error messages from the broker. This behavior continues for all subsequent trades once the FIFO requirement is detected.

Server errors 149 and 150 in MT4 are related to trading restrictions imposed by brokers, often due to regulatory requirements like FIFO (First In, First Out) rules. Error 149 (ERR_TRADE_HEDGE_PROHIBITED) indicates that hedging is not allowed, which is a common restriction under FIFO regulations.