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• The EA uses an internal variable to remember "trade open", which resets to false on restart.
• A signal is still valid after the restart, so the EA acts on it again.
• Two terminals run the same EA on the same account after a recovery.

• On start, scan open positions and pending orders by magic number and symbol, and rebuild the internal state from them.
• Store the time of the last signal acted on in a global variable of the terminal or a file, and refuse to act on the same signal twice.
• Use a lock file or a global variable with the terminal ID, so a second instance knows it's not alone.

FXS London Scalper wrote: Sun Nov 01, 2026 1:53 pm An EA that restarts, after a VPS reboot or a platform update, needs to know what it already did. Otherwise it can open a duplicate position.

Common causes of duplicates:

• The EA uses an internal variable to remember "trade open", which resets to false on restart.
• A signal is still valid after the restart, so the EA acts on it again.
• Two terminals run the same EA on the same account after a recovery.

Solutions:

• On start, scan open positions and pending orders by magic number and symbol, and rebuild the internal state from them.
• Store the time of the last signal acted on in a global variable of the terminal or a file, and refuse to act on the same signal twice.
• Use a lock file or a global variable with the terminal ID, so a second instance knows it's not alone.

Testing: restart the terminal on purpose on a demo account while a position is open, and in the middle of a signal bar. Check the log for duplicate actions.

This is one of those features nobody notices until it fails.

How do you handle restarts in your EAs?