opencode-skill/skills/mql-developer/mql5-ea-troubleshooting/SKILL.md

name, description

name	description
mql5-ea-troubleshooting	MQL5 EA runtime errors and attach failures — init failures, INVALID_HANDLE 32757, build-specific enum differences

MQL5 EA Troubleshooting

Common runtime errors (attach failed)

Error 32757 (0x8001 = E_HANDLE / INVALID_HANDLE)

Usually means an indicator handle creation failed, or a function call/argument mismatch in OnInit().

Stack mismatch diagnosis:

// Call site passes 9 args:
g_orderManager.Init(g_symbol, InputMagicNumber, InputComment,
                    InputEntryPrice, InputSL, InputTP,
                    InputMaxFollowOrders, InputUseTrailingSL,
                    InputFollowDelayBars);  // ← 9 args

// But declaration only accepts 8:
void Init(string symbol, int magicNumber, string comment,
          double inputEntry, double inputSL, double inputTP,
          int maxFollow, bool useTrailing, int followDelayBars);  // ← 8 params
//                                                                                         ↑ stack corrupted

Fix: match declaration to call.

Indicator handle failure:

• iATR(symbol, PERIOD_M5) → in some builds requires 3 params: iATR(symbol, PERIOD_M5, period)
• iATR(handle) returns INVALID_HANDLE if symbol/timeframe unavailable
• Always check: if(handle == INVALID_HANDLE) return INIT_FAILED;

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Build-specific enums (tested on build 3570+)

Enum	Wrong	Correct
ATR params	iATR(sym, TF) (2 args)	iATR(sym, TF, period) (3 args)
Account margin	ACCOUNT_MARGIN_MODE_NETTING	ACCOUNT_MARGIN_MODE_RETAIL_NET
Account free margin	ACCOUNT_FREEMARGIN (deprecated)	ACCOUNT_MARGIN_FREE
Symbol contract size	SYMBOL_CONTRACT_SIZE	SYMBOL_TRADE_CONTRACT_SIZE
Margin rate	SYMBOL_MARGIN_RATE (doesn't exist)	SYMBOL_MARGIN_HEDGED or use OrderCalcMargin()
TRADE_TRANSACTION	TRADE_TRANSACTION_POSITION_CLOSE, _OPEN don't exist	Use TRADE_TRANSACTION_DEAL_ADD + TRADE_TRANSACTION_POSITION
CTrade.SetComment()	doesn't exist	Pass comment string directly to Buy()/Sell()

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Type coercion warnings (benign — still compile)

• SymbolInfoInteger() returns long; assign to double with explicit cast: (double)SymbolInfoInteger(sym, SYMBOL_SPREAD)
• rates[].tick_volume is long; cast: (double)rates[0].tick_volume

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Debug approach for attach/init failures

1. Check if error is an INIT_* code ( INIT_PARAMETERS_INCORRECT = 5, INIT_FAILED = 7)
2. If not INIT code → look for INVALID_HANDLE or E_HANDLE
3. Search all files for IndicatorCreate, iATR, iAC, iADX — ensure all handles checked
4. Count arguments in every Init/constructor call vs. declaration
5. Check global-scope code that runs before OnInit() (including class member constructors)