MT5 · Runtime errors
MT5 5009 · The file must be opened for writing | YI GOLD
ERR_FILE_NOTTOWRITE
Official meaning
The file must be opened for writing
Possible causes · YI GOLD suggestions
Paths, access modes, formats, handles or permissions do not meet requirements.
Troubleshooting · YI GOLD suggestions
Check permitted terminal sandbox paths, names, access flags, formats and handles. Record open failures without granting permissive directory access.