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[Error:4756-10014] Trade request sending failed : Invalid volume in the request


Introduction

Have you seen this message?

Error: 4756-10014 Trade request sending failed : Invalid volume in the request

This error occurs when the volume (lot size) you send in an order does not comply with the rules defined for that symbol/pair in MetaTrader. In this guide you’ll learn what this means and how to fix it.

1. What does “Invalid volume” mean?

Each instrument in MetaTrader (forex, CFDs, etc.) has specific parameters defined by your broker:

👉 If the lot size you send is below the minimum, above the maximum, or not a valid multiple of the step, MetaTrader will reject the order with this error.

2. How to check symbol specifications in MetaTrader

To confirm the valid volume rules for a symbol (example: EURUSD):

  1. Open MetaTrader (MT4 or MT5).
  2. In the Market Watch window, find your symbol.
  1. Right-click on the symbol → select Specification.
  1. Review the key parameters:

Parameters

Contract size – How much 1 lot represents
Minimal volume – The smallest lot size you can trade
Maximal volume – The largest lot size you can trade
Volume step – The increment between allowed lot sizes
(Example: if minimum = 0.01 and step = 0.01, valid values are 0.01, 0.02, 0.03, etc.)

3. Fixing the error via EA Settings (Order_Size)

To fix this error is by adjusting the Order_Size parameter directly inside the EA settings of TradeAdapter.

When you set a fixed value here, the EA will use this value instead of the one coming from TradingView alerts. This ensures that the lot size always matches the broker’s requirements.

How to do it:

  1. In MetaTrader, open the Navigator, go to Expert Advisors, and double-click on the TradeAdapter EA.
  2. In the configuration window, go to the Inputs tab.
  3. Locate the field Order_Size.
  4. Enter a valid lot size according to the symbol specification (e.g. 0.10 or 0.01 depending on the broker’s minimum/step).
  5. Click OK to save.

✅ Example: if the symbol allows min = 0.01, max = 500, step = 0.01 → setting 0.10 here will work fine.

❌ Do not set values outside the allowed range (like 0.005 or 0.015).

This method is useful if you want to “override” the lot size sent from TradingView and always use a consistent, broker-approved value for that symbol.