Oracle Message LFI-00137 - Unable to perform string on a file object that is string.

ERRORUnable to perform string on a file object that is string.
CAUSEUnable to perform an LFI operation on a file object for the given reason.
ACTIONTake the appropriate corrective measure. For example if a file is supposed to be opened before the operation can be performed, client code will need to open the file first.