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MQL4 ERR_INVALID_PRICE_PARAM

MQL4 error 4107: correct the price parameter

MQL4 error 4107 invalid price parameter maps to ERR_INVALID_PRICE_PARAM: invalid price parameter for trade function. A price passed to a trade function is structurally invalid for the symbol or operation. For API calls, check the return value and capture GetLastError after a documented failure. Critical runtime errors require preventive guards and inspection of the terminal log.

Open MQL4 Coding AgentReview the code example

Open the Coding Agent, then choose MQL4 from the language menu.

PriceParameterDiagnostic.mq4MQL4
#property strict
#property script_show_inputs

input double Lots = 0.10;
input int Slippage = 3;

void OnStart()
  {
   if(!IsTradeAllowed())
     {
      Print("Trading is not currently allowed or the trade context is busy.");
      return;
     }

   RefreshRates();
   double price = NormalizeDouble(Ask, Digits);
   ResetLastError();
   int ticket = OrderSend(Symbol(), OP_BUY, Lots, price, Slippage,
                          0, 0, "diagnostic", 0, 0, clrNONE);

   if(ticket >= 0)
     {
      Print("Order opened. Ticket ", ticket);
      return;
     }

   int error_code = GetLastError();
   Print("OrderSend failed. error=", error_code,
         " symbol=", Symbol(), " lots=", DoubleToString(Lots, 2),
         " ask=", DoubleToString(price, Digits));
  }
  • Official meaning: invalid price parameter for trade function
  • Check API results or the runtime failure log
  • Capture relevant inputs and error context
  • Retry only when the condition can change

What MQL4 error 4107 means

The official MQL4 runtime table names error 4107 ERR_INVALID_PRICE_PARAM and defines it as “invalid price parameter for trade function.” A price passed to a trade function is structurally invalid for the symbol or operation.

An error-state value is supporting context, not proof that a call failed or a diagnosis of the whole EA. For noncritical API failures, read the return value and then GetLastError, which resets _LastError. Critical errors such as zero division terminate execution, so code after the failing expression cannot serve as a recovery handler.

Check these conditions before editing the strategy

Start with the inputs and external state that existed at the failure point. A later log entry or a successful call can overwrite the useful context.

  • The price is zero, negative, or not available for the symbol
  • Digits or tick-size normalization is wrong
  • Stop, limit, or pending price is on an invalid side of the market
  • A multi-symbol EA uses the chart symbol Point or Digits

Fix the cause, then choose a retry policy

Recalculate all price fields from current symbol data. Repeating the same invalid parameter will not make it valid.

Keep the original trading and risk rules intact. A workaround that widens stops, increases volume, changes an account setting, or ignores a failed return value can hide the symptom while changing the system.

CheckAction
The price is zero, negative, or not available for the symbolReject zero and non-finite prices before the trade call.
Digits or tick-size normalization is wrongNormalize with properties from the exact order symbol.
Stop, limit, or pending price is on an invalid side of the marketValidate price direction for the selected order type.
A multi-symbol EA uses the chart symbol Point or DigitsDo not reuse chart-symbol price properties in a multi-symbol request.

Review the complete example

The script creates a normalized current-symbol Ask and records it on failure. Multi-symbol code needs symbol-specific Bid, Ask, Point, and Digits values.

This script can submit one market buy with no SL or TP. It omits volume, margin, quote-freshness, and duplicate-order controls. Add the required controls and use only a demo account before evaluating this diagnostic.

PriceParameterDiagnostic.mq4MQL4
#property strict
#property script_show_inputs

input double Lots = 0.10;
input int Slippage = 3;

void OnStart()
  {
   if(!IsTradeAllowed())
     {
      Print("Trading is not currently allowed or the trade context is busy.");
      return;
     }

   RefreshRates();
   double price = NormalizeDouble(Ask, Digits);
   ResetLastError();
   int ticket = OrderSend(Symbol(), OP_BUY, Lots, price, Slippage,
                          0, 0, "diagnostic", 0, 0, clrNONE);

   if(ticket >= 0)
     {
      Print("Order opened. Ticket ", ticket);
      return;
     }

   int error_code = GetLastError();
   Print("OrderSend failed. error=", error_code,
         " symbol=", Symbol(), " lots=", DoubleToString(Lots, 2),
         " ask=", DoubleToString(price, Digits));
  }
Where Pineify fits

Move from the rule to editable MQL4 source

Pineify can generate or revise one self-contained .mq4 file with MQL4-specific reference context. Its independent static checker returns MetaEditor diagnostics so you can repair source issues before testing in your own MT4 environment.

Open MQL4 Coding Agent

Static diagnostics do not prove runtime behavior, backtest results, broker compatibility, or live-trading safety.

Pineify MQL4 Coding Agent with MQL4 selected and an editable MetaTrader 4 code artifact

A practical workflow

  1. 1

    Locate the failed operation

    Check the API result, or the terminal log and source location for a critical runtime failure.

  2. 2

    Capture the error once

    For a recoverable API failure, capture GetLastError immediately. For a terminated program, preserve the terminal log. Record error 4107 and the inputs relevant to the failed operation.

  3. 3

    Correct the triggering condition

    Reject zero and non-finite prices before the trade call.

  4. 4

    Retest in the target environment

    Compile the revised source, then test with the same MT4 build, broker, symbol, account permissions, and market state.

Frequently asked questions

What does MQL4 error 4107 invalid price parameter mean?

ERR_INVALID_PRICE_PARAM means invalid price parameter for trade function. Use the API result or critical runtime log, together with the relevant inputs, to identify the failed operation.

What usually causes MQL4 error 4107?

The price is zero, negative, or not available for the symbol. Digits or tick-size normalization is wrong. Stop, limit, or pending price is on an invalid side of the market. A multi-symbol EA uses the chart symbol Point or Digits.

Should an EA retry after error 4107?

Recalculate all price fields from current symbol data. Repeating the same invalid parameter will not make it valid.

Why should GetLastError be called immediately?

For a noncritical API failure it reports the current _LastError value and resets it. A delayed read may describe another call. It cannot recover execution after a critical error has terminated the program.

Can Pineify fix MQL4 error 4107?

Pineify can revise a self-contained .mq4 file, add validation and error logging, and return static MetaEditor diagnostics. It cannot prove broker acceptance, account permissions, market availability, or live execution.

Compile and test the final source in the MetaTrader 4 build, broker, symbol, and account environment you plan to use.

Continue with one reviewable MQL4 file

Define the requirement, inspect the generated source, repair diagnostics, and test the behavior in your own MT4 environment.

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