MQL5 runtime error reference
MQL5 error 5039 officially means "Number of parameters exceeds the number of format specifiers." PrintFormat, StringFormat, or another formatted call received more value arguments than the format string contains placeholders for. Make the number and types of format specifiers match the supplied values. Prefer explicit specifiers for ulong, double precision, enums, and strings, and let the compiler warning remain visible. Capture GetLastError immediately around the failing call so an older error is not mistaken for the current failure.
Open the Coding Agent and choose MQL5 from the language menu.
ulong ticket=123456;
double volume=0.10;
string symbol=_Symbol;
// Three specifiers for three values.
PrintFormat("ticket=%I64u symbol=%s volume=%.2f",
ticket,symbol,volume);PrintFormat, StringFormat, or another formatted call received more value arguments than the format string contains placeholders for. The numeric value is listed in the official runtime error table, which is separate from MetaEditor compilation errors and trade server return codes.
Reset the last-error state before the suspected call, save its direct return value, and read GetLastError immediately afterward. This produces a causal log instead of a stale code.
Preserve the exact parameters and terminal context that produced the failure. Check one precondition at a time before adding retries.
Make the number and types of format specifiers match the supplied values. Prefer explicit specifiers for ulong, double precision, enums, and strings, and let the compiler warning remain visible.
After the repair, test both the expected path and a deliberately invalid input. The second test confirms that the diagnostic branch still exposes failures.
The corrected format has one type-compatible placeholder for each argument. This prevents runtime error 5039 and produces a readable diagnostic.
A clean compile or a cleared error code does not prove strategy logic, broker compatibility, backtest quality, or live-trading safety. Reproduce the result in the target MetaTrader 5 terminal and account environment.
ulong ticket=123456;
double volume=0.10;
string symbol=_Symbol;
// Three specifiers for three values.
PrintFormat("ticket=%I64u symbol=%s volume=%.2f",
ticket,symbol,volume);Pineify can generate or revise MQL5 source and use MQL5 compilation diagnostics during the coding workflow. Keep the exact error, source location, program type, and intended behavior in the request so the change remains reviewable.
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Call ResetLastError directly before the suspected function so the next code belongs to that operation.
Save the function return value, every input, and GetLastError. Confirm that the captured runtime code is 5039.
Count every percent specifier, excluding an escaped %% literal. Match %s, %d, %u, %I64u, and floating-point specifiers to value types. Remove stale values after editing a log message. Use EnumToString when a readable enum value is desired.
Compile the changed source, repeat the failing operation, and test the surrounding EA or indicator behavior in MetaTrader 5.
The official runtime error table defines 5039 as "Number of parameters exceeds the number of format specifiers."
No in this context. It is a terminal runtime code. Compiler diagnostics and MqlTradeResult.retcode values use separate code tables.
The terminal stores the last runtime error. Resetting it before the suspected call makes the following GetLastError value easier to attribute to that call.
Last verified against the linked official references on . Compile and test the final source in the MetaTrader 5 build, broker, symbol, and account environment you plan to use.
Provide the exact diagnostic and intended behavior, inspect the generated change, compile it, and verify it in your MT5 test environment.
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