backend_error

The terminal returned an error for this operation; the MetaTrader code is in `code` or `mt5Code`.

HTTP 500, 502. Unknown: it may have executed. Resolve it with the same idempotency key before acting.

Likely causes:

• The terminal refused or failed the call.
• The connection to the terminal failed mid-call.

What to do: Reads: retry. Trades: do not resend blindly; repeat only with the same Idempotency-Key, which answers with the real outcome.

Retry: Only with the same Idempotency-Key (or clientId). The first attempt may have executed; never resend a trade blindly.

Listed under Accounts and terminals in Errors. Send the error’s requestId to support and we can find the request.