MRPC_VALIDATION

Terminal route error (`/{mt4|mt5}/{id}/…`): a parameter is missing or invalid.

HTTP 400. Nothing reached the broker.

Likely causes:

• A required query or body field is missing.
• A value has the wrong type or range.

What to do: Fix the request; the message names the parameter.

Retry: No. The same request gets the same answer; change something first.

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