MT5 error 4302: Symbol is not selected in Market Watch (ERR_MARKET_NOT_SELECTED)

What it means

You see this code in GetLastError() in MQL5, after a function fails.

The terminal only streams prices for symbols shown in Market Watch. Asking for live data on a symbol that exists but isn't selected fails with 4302.

It is easy to fix and common in code that trades many symbols.

Common causes

• A symbol that was never added to Market Watch.
• A symbol removed from Market Watch by hand or by another program.
• A fresh terminal profile with only a default list of symbols.

How to fix it

• Call SymbolSelect(name, true) before you read prices or trade.
• In Python, mt5.symbol_select(name, True) does the same.
• Wait for the first tick after selecting before you send an order.

Example in MQL5:

bool Ready(const string sym)
{
   if(!SymbolInfoInteger(sym, SYMBOL_SELECT) && !SymbolSelect(sym, true))
   {
      Print("Could not add ", sym, " to Market Watch, error ", GetLastError());
      return false;
   }
   MqlTick t;
   return SymbolInfoTick(sym, t) && t.time > 0;   // a price has arrived
}

Is it safe to retry?

Yes, after selecting the symbol.

Could the order have executed?

Related codes

• MT5 error 4301: Unknown symbol (ERR_MARKET_UNKNOWN_SYMBOL)
• MT5 error 10021: No quotes to process the request (TRADE_RETCODE_PRICE_OFF)
• MT5 Python error -4: Not found (RES_E_NOT_FOUND)

Related MT5 Python functions

• mt5.symbol_info() in MetaTrader5 Python: read a symbol's settings and limits
• mt5.symbol_info_tick() in MetaTrader5 Python: get the latest bid and ask
• mt5.symbol_select() in MetaTrader5 Python: add a symbol to Market Watch
• mt5.copy_rates_from() in MetaTrader5 Python: get bars back from a date
• mt5.copy_ticks_from() in MetaTrader5 Python: get ticks forward from a date

All MetaTrader error codes