This error may occur due to one of the following reasons:
The Trade Operation is No Longer Available
If trading from multiple devices, an operation may have already been completed on one device while another device attempts to execute the same action. For example, if an order was closed on the MT4 mobile app but a closure attempt is also made on a desktop terminal, this error may appear.
Solution: Ensure all trading terminals are synchronized. A poor internet connection may cause discrepancies. Log out of all open trading terminals and log back into a single one to resolve this issue.
2. Invalid Trade Parameters
This error may occur when entering incorrect values for specific trade parameters, either manually or through an Expert Advisor (EA). For example, using an invalid trade volume for a specific account type may trigger this error.
Solution: Check EA settings and ensure they comply with the trade limitations of your account type. If the issue persists, contact Taurex Support for further assistance.