$ERR_FILOPT
21
Invalid operation for file type
You’ve issued an I/O statement that was not allowed by the mode in which the file was opened. For example, you would get this error if you attempted to write to a file that was opened in input mode.
21
Invalid operation for file type
You’ve issued an I/O statement that was not allowed by the mode in which the file was opened. For example, you would get this error if you attempted to write to a file that was opened in input mode.