utl_file.INVALID_OPERATION error

create directory mydir as  '/home/';

declare

 v_check_FHandle        UTL_FILE.FILE_TYPE;
  v_input_dir            varchar2(100) :='MYDIR';
  v_input_file            varchar2(100);
  v_check_stmt               VARCHAR2(2000);
  v_check_cnt           number:=0;
  v_check_flag          boolean := TRUE;

      ---------------------------------------------
      -- Checking the Existance of the file
      ---------------------------------------------
begin
      BEGIN
      v_input_file := 'h.txt';
          v_check_FHandle := utl_file.fopen(v_input_dir,v_input_file,'R');
          utl_file.get_line(v_check_FHandle, v_check_stmt);
          v_check_cnt := v_check_cnt + 1;
          utl_file.fclose(v_check_Fhandle);
          IF v_check_cnt > 0 then
            v_check_flag := FALSE;
          END IF;
        EXCEPTION
          When NO_DATA_FOUND then
          -- the file exists, but has zero bytes
          utl_file.fclose(v_check_Fhandle);
            v_check_flag := TRUE;
  WHEN utl_file.invalid_mode THEN
    RAISE_APPLICATION_ERROR (-20051, 'Invalid Mode Parameter');
  WHEN utl_file.invalid_path THEN
    RAISE_APPLICATION_ERROR (-20052, 'Invalid File Location');
  WHEN utl_file.invalid_filehandle THEN
    RAISE_APPLICATION_ERROR (-20053, 'Invalid Filehandle');
  WHEN utl_file.invalid_operation THEN
    RAISE_APPLICATION_ERROR (-20054, 'Invalid Operation');
  WHEN utl_file.read_error THEN
    RAISE_APPLICATION_ERROR (-20055, 'Read Error');
  WHEN utl_file.internal_error THEN
    RAISE_APPLICATION_ERROR (-20057, 'Internal Error');
  WHEN utl_file.charsetmismatch THEN
    RAISE_APPLICATION_ERROR (-20058, 'Opened With FOPEN_NCHAR
    But Later I/O Inconsistent');
 WHEN utl_file.file_open THEN
    RAISE_APPLICATION_ERROR (-20059, 'File Already Opened');
 WHEN utl_file.invalid_maxlinesize THEN
    RAISE_APPLICATION_ERROR(-20060,'Line Size Exceeds 32K');
 WHEN utl_file.invalid_filename THEN
    RAISE_APPLICATION_ERROR (-20061, 'Invalid File Name');
 WHEN utl_file.access_denied THEN
    RAISE_APPLICATION_ERROR (-20062, 'File Access Denied By');
 WHEN utl_file.invalid_offset THEN
    RAISE_APPLICATION_ERROR (-20063,'FSEEK Param Less Than 0');
 WHEN others THEN
    RAISE_APPLICATION_ERROR (-20099, 'Unknown UTL_FILE Error');
     end;
    BEGIN
   -- Open the input file for reading
   if v_check_flag then
   v_check_FHandle:=UTL_FILE.FOPEN(v_input_dir,v_input_file,'R');
   end if;
   DBMS_OUTPUT.PUT_LINE('File Opened for read.');
    end;
end;
/

This code works for me..can you paste your full code. the code you have pasted seems to be ok only but it is partial

.looks like you have exception handler more than once in your full set of code..paste the code from where you are calling this code...