Nixstatsagent Python error

Few days ago, I uninstalled nixstats from a backup server because it was somehow taking lot of cpu. Later I found the culprit to be updatedb making it unaccessible.

I uninstalled nixstats to bring load low and on reinstallation, it didn't show up on panel. I ran nixstatsagent command and it throws python error

Exception in thread Thread-1:
Traceback (most recent call last):
  File "/usr/lib64/python2.7/threading.py", line 811, in __bootstrap_inner
    self.run()
  File "/usr/lib64/python2.7/threading.py", line 764, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/lib/python2.7/site-packages/nixstatsagent/nixstatsagent.py", line 402, in _data
    json.dumps(collection, indent=2, sort_keys=True))
  File "/usr/lib64/python2.7/json/__init__.py", line 250, in dumps
    sort_keys=sort_keys, **kw).encode(obj)
  File "/usr/lib64/python2.7/json/encoder.py", line 209, in encode
    chunks = list(chunks)
  File "/usr/lib64/python2.7/json/encoder.py", line 431, in _iterencode
    for chunk in _iterencode_list(o, _current_indent_level):
  File "/usr/lib64/python2.7/json/encoder.py", line 332, in _iterencode_list
    for chunk in chunks:
  File "/usr/lib64/python2.7/json/encoder.py", line 408, in _iterencode_dict
    for chunk in chunks:
  File "/usr/lib64/python2.7/json/encoder.py", line 442, in _iterencode
    o = _default(o)
  File "/usr/lib64/python2.7/json/encoder.py", line 184, in default
    raise TypeError(repr(o) + " is not JSON serializable")
TypeError: IOError(2, 'No such file or directory') is not JSON serializable

Is it error related to python misfunctioning or nixstats misconfiguration/bug?

P.S. Before everyone start commenting "Welcome to helpdesk" blah blah. I had already contacted nixstats on livechat and he seems to be away/busy.