MT5 · Runtime errors
MT5 5309 · A too long string parameter while setting the property of a custom symbol | YI GOLD
ERR_CUSTOM_SYMBOL_PARAMETER_LONG
Official meaning
A too long string parameter while setting the property of a custom symbol
Possible causes · YI GOLD suggestions
Parameter types, counts or ranges do not match the function signature.
Troubleshooting · YI GOLD suggestions
Compare each argument and reference mode with the official signature. Validate ranges and preserve relevant failure context.