C:\Program Files\Bitcoin\pywallet>walletco.py --wpath=m:\bitcoin\old\ --nwpath=m
:\bitcoin\new\
Dumping...
Traceback (most recent call last):
  File "C:\Program Files\Bitcoin\pywallet\walletco.py", line 114, in
    main()
  File "C:\Program Files\Bitcoin\pywallet\walletco.py", line 89, in main
    json_db = json.loads(a.read())
  File "C:\Python27\lib\json\__init__.py", line 326, in loads
    return _default_decoder.decode(s)
  File "C:\Python27\lib\json\decoder.py", line 360, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "C:\Python27\lib\json\decoder.py", line 378, in raw_decode
    raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded