MT5 · Runtime errors
MT5 5016 · String size must be specified, because the file is opened as binary | YI GOLD
ERR_FILE_BINSTRINGSIZE
Official meaning
String size must be specified, because the file is opened as binary
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.