MT4 · Trade return codes
MT4 150 · An attempt to close an order contravening the FIFO rule | YI GOLD
ERR_TRADE_PROHIBITED_BY_FIFO
Official meaning
An attempt to close an order contravening the FIFO rule
Possible causes · YI GOLD suggestions
Determine the cause from the official meaning, the triggering function and terminal logs.
Troubleshooting · YI GOLD suggestions
Check permissions, sessions, symbol specifications, quotes and request parameters. Reproduce in a demo account. Do not retry rejected requests indefinitely.