Debugging Common EA Errors

Cause: Stop loss or take profit too close to current price

// Check minimum stop level
double minStop = MarketInfo(Symbol(), MODE_STOPLEVEL) * Point;
if (MathAbs(price - sl) < minStop) {
  sl = price - minStop; // Adjust stop
}

Prevention: Always check MODE_STOPLEVEL before placing orders

Cause: Lot size outside allowed range or wrong step

// Normalize lot size
double minLot = MarketInfo(Symbol(), MODE_MINLOT);
double maxLot = MarketInfo(Symbol(), MODE_MAXLOT);
double lotStep = MarketInfo(Symbol(), MODE_LOTSTEP);
lots = MathFloor(lots / lotStep) * lotStep;
lots = MathMax(minLot, MathMin(maxLot, lots));

Prevention: Always normalize lots before OrderSend

Cause: Insufficient margin for the trade

// Check margin before trading
double marginRequired = MarketInfo(Symbol(), MODE_MARGINREQUIRED) * lots;
if (AccountFreeMargin() < marginRequired * 1.5) {
  Print("Insufficient margin");
  return;
}

Prevention: Calculate margin requirements before every trade

Cause: Price changed during order processing

// Retry with new price
int retries = 3;
while (retries > 0) {
  RefreshRates();
  if (OrderSend(...) > 0) break;
  retries--;
  Sleep(100);
}

Prevention: Implement retry logic with RefreshRates()

Cause: Trying to modify at same price or too close

// Check if modification actually needed
if (MathAbs(newSL - currentSL) < Point) {
  return; // No change needed
}

Prevention: Compare old and new values before modifying

Cause: Accessing indicator buffer with invalid index

// Always check array size
if (ArraySize(buffer) > index && index >= 0) {
  value = buffer[index];
}

Prevention: Validate indices before array access

Add logging at key decision points

Print("Signal Check: ", signalBuy, " / ", signalSell);
Print("Spread: ", MarketInfo(Symbol(), MODE_SPREAD));
Print("Account Free Margin: ", AccountFreeMargin());
Print("Attempting order: ", lots, " lots at ", Ask);

Centralized error handling with context

void LogError(string location) {
  int error = GetLastError();
  if (error != 0) {
    Print("ERROR in ", location, ": ", error, 
          " - ", ErrorDescription(error));
  }
}

Track EA state transitions

enum EAState { WAITING, SIGNAL, ENTRY, MANAGING, EXIT };
EAState currentState = WAITING;

void SetState(EAState newState) {
  Print("State: ", EnumToString(currentState), 
        " -> ", EnumToString(newState));
  currentState = newState;
}

Confirm trades executed correctly

int ticket = OrderSend(...);
if (ticket > 0) {
  if (OrderSelect(ticket, SELECT_BY_TICKET)) {
    Print("Trade confirmed: ", OrderSymbol(), 
          " @ ", OrderOpenPrice());
  }
} else {
  Print("Trade failed: ", GetLastError());
}