How to Fix Please Verify Operation Parameters in MT4?

If you use Expert advisors very often, you can see errors like this: “Please verify operation parameters and try again later.” This Order sends error three is very dangerous because this error blocks future trades from being executed, and Expert advisors become useless.

The OrderSend Error 3 or invalid trade parameters in MT4 is called ERR_INVALID_TRADE_PARAMETERS, and it is often an error such as a standard error in MT4.

Why do invalid trade parameter errors in MT4 occur?

Invalid trade parameters errors in MT4 occur because of one of the following reasons:

  • If the MQL programmer types an incorrect operation in the OrderSend() function.
  • Wrong-defined slippage in input. Slippage needs to be 0 or greater.
  • Order is not defined well because incorrect order tickets are passed on the function OrderModify(). Add a piece of code “if (ticket > 0)” before OrderModify().

In OrderSend() function, you can define only six operations:

  • OP_BUY will Open an extended position.
  • OP_SELL will Open a short position.
  • OP_BUYLIMIT will open a buy limit order.
  • OP_SELLLIMIT will open a sell limit order.
  • OP_BUYSTOP will open a stop order.
  • OP_SELLSTOP will open a stop order.

How to Fix Please Verify Operation Parameters in MT4?

To fix an invalid trade parameters error in MT4 marked as ERR_INVALID_TRADE_PARAMETERS, you must first check the MQL code is a slippage positive number defined in the input. If slippage is a positive number, then you need to check the ticketing system in MQL, and you need to add if (ticket > 0) in front of the OrderModify() function such as:

if (ticket > 0)

Usually, if you have this error, the problem is in the expert advisor code, and you can ask the programmer for help. Please see all significant errors in MT4 below:


ErrorError IDDescription
ERR_NO_ERROR0No error returned.
ERR_NO_RESULT1No error returned, but the result is unknown.
ERR_COMMON_ERROR2Common error.
ERR_INVALID_TRADE_PARAMETERS3Invalid trade parameters.
ERR_SERVER_BUSY4Trade server is busy.
ERR_OLD_VERSION5Old version of the client terminal.
ERR_NO_CONNECTION6No connection with trade server.
ERR_NOT_ENOUGH_RIGHTS7Not enough rights.
ERR_TOO_FREQUENT_REQUESTS8Too frequent requests.
ERR_MALFUNCTIONAL_TRADE9Malfunctional trade operation.
ERR_ACCOUNT_DISABLED64Account disabled.
ERR_INVALID_ACCOUNT65Invalid account.
ERR_TRADE_TIMEOUT128Trade timeout.
ERR_INVALID_PRICE129Invalid price.
ERR_INVALID_STOPS130Invalid stops.
ERR_INVALID_TRADE_VOLUME131Invalid trade volume.
ERR_MARKET_CLOSED132Market is closed.
ERR_TRADE_DISABLED133Trade is disabled.
ERR_NOT_ENOUGH_MONEY134Not enough money.
ERR_PRICE_CHANGED135Price changed.
ERR_OFF_QUOTES136Off quotes.
ERR_BROKER_BUSY137Broker is busy.
ERR_ORDER_LOCKED139Order is locked.
ERR_LONG_POSITIONS_ONLY_ALLOWED140Long positions only allowed.
ERR_TOO_MANY_REQUESTS141Too many requests.
ERR_TRADE_MODIFY_DENIED145Modification denied because an order is too close to market.
ERR_TRADE_CONTEXT_BUSY146Trade context is busy.
ERR_TRADE_EXPIRATION_DENIED147Expirations are denied by broker.
ERR_TRADE_TOO_MANY_ORDERS148The amount of opened and pending orders has reached the limit set by a broker.


To resolve this issue, especially if you’re working with MQL code, there are various considerations to look into:

  1. Check Slippage: In MT4’s MQL language, the slippage value dictates how much an executed price can differ from the requested price before the trade is rejected. If your slippage is set to a negative number or an unrealistic number, it could cause the trade to fail.
    • Ensure that your slippage is a reasonable positive number.
    • For instance, if you’re trading major forex pairs, a slippage value of 2 to 5 pips (20 to 50 points in a 5-digit broker) might be appropriate.
  2. Check the Ticketing System in MQL:
    • The system uses a ticketing approach when placing or modifying orders through MQL4. Every order has a unique identification number, often called a “ticket.”
    • Before modifying an order OrderModify(), you should ensure that the ticket you’re trying to modify exists and is valid. Hence, you should always check the ticket’s validity before proceeding.
  3. Check Other Trade Parameters:
    • Validate the price you’re trying to open or modify the order. It may be rejected if it’s too far from the current market price (beyond just slippage).
    • Ensure that the StopLoss and TakeProfit levels are set correctly. Depending on the broker and account settings, there may be limitations on how close these can be to the entry price.
    • If you’re working with lot sizes, ensure your volume is within the acceptable range for your broker and account type. Too small or too large lot sizes can cause errors.
  4. Other Considerations:
    • Brokers can have specific trading restrictions, such as a freeze level that prevents you from modifying or closing an order when the price is too close to the market price.
    • Some trading conditions like market closures, high volatility events, or lack of liquidity can lead to these errors.
    • Ensure that trading isn’t disabled on your MT4 platform and you’re not trying to trade during off-market hours.

In conclusion, the “Please Verify Operation Parameters” message in MT4 requires the trader or developer to verify that all parameters associated with a trade are correct and fall within acceptable limits. Proper debugging, logging, and frequent testing of EAs or scripts can help quickly identify and rectify such issues.





Igor has been a trader since 2007. Currently, Igor works for several prop trading companies. He is an expert in financial niche, long-term trading, and weekly technical levels. The primary field of Igor's research is the application of machine learning in algorithmic trading. Education: Computer Engineering and Ph.D. in machine learning. Igor regularly publishes trading-related videos on the Fxigor Youtube channel. To contact Igor write on:

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