"invalid end of string" crash

[dandv]

Unfortunately I don't have more information about this than the output:

Server           Opid   Client           Type     Sec   Locks                          Namespace                                         Query
localhost:27017  92510  127.0.0.1:35554  query    0     r                              stockbase-prod.companies                          query not recording (too large)

Traceback (most recent call last):
  File "/usr/local/bin/motop", line 5, in <module>
    pkg_resources.run_script('motop==4.1', 'motop')
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 499, in run_script
    self.require(requires)[0].run_script(script_name, ns)
  File "/usr/lib/python2.7/dist-packages/pkg_resources.py", line 1235, in run_script
    execfile(script_filename, namespace, namespace)
  File "/usr/local/lib/python2.7/dist-packages/motop-4.1-py2.7.egg/EGG-INFO/scripts/motop", line 4, in <module>
    motop.run()
  File "/usr/local/lib/python2.7/dist-packages/motop-4.1-py2.7.egg/libmotop/motop.py", line 95, in run
    queryScreen.action()
  File "/usr/local/lib/python2.7/dist-packages/motop-4.1-py2.7.egg/libmotop/queryscreen.py", line 309, in action
    block.reset()
  File "/usr/local/lib/python2.7/dist-packages/motop-4.1-py2.7.egg/libmotop/queryscreen.py", line 221, in reset
    for op in server.currentOperations(hideReplicationOperations):
  File "/usr/local/lib/python2.7/dist-packages/motop-4.1-py2.7.egg/libmotop/server.py", line 109, in currentOperations
    operations = self.__execute(self.__connection.admin.current_op)
  File "/usr/local/lib/python2.7/dist-packages/motop-4.1-py2.7.egg/libmotop/server.py", line 64, in __execute
    return procedure(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/pymongo/database.py", line 550, in current_op
    return self['$cmd.sys.inprog'].find_one()
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/pymongo/collection.py", line 721, in find_one
    for result in cursor.limit(-1):
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/pymongo/cursor.py", line 1038, in next
    if len(self.__data) or self._refresh():
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/pymongo/cursor.py", line 982, in _refresh
    self.__uuid_subtype))
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/pymongo/cursor.py", line 925, in __send_message
    self.__compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/pymongo/helpers.py", line 117, in _unpack_response
    compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 533, in decode_all
    tz_aware, uuid_subtype, compile_re))
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 331, in _elements_to_dict
    data, position, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 320, in _element_to_dict
    data, position, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 170, in _get_array
    as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 159, in _get_object
    encoded, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 331, in _elements_to_dict
    data, position, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 320, in _element_to_dict
    data, position, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 159, in _get_object
    encoded, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 331, in _elements_to_dict
    data, position, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 320, in _element_to_dict
    data, position, as_class, tz_aware, uuid_subtype, compile_re)
  File "/usr/local/lib/python2.7/dist-packages/pymongo-2.7.1-py2.7-linux-x86_64.egg/bson/__init__.py", line 149, in _get_string
    raise InvalidBSON("invalid end of string")
bson.errors.InvalidBSON: invalid end of string