TypeError: __init__() got an unexpected keyword argument 'item_type'

[S-IMEN]

ryu-manager
Traceback (most recent call last):
File "/usr/local/bin/ryu-manager", line 11, in
load_entry_point('ryu==4.26', 'console_scripts', 'ryu-manager')()
File "/usr/local/lib/python2.7/dist-packages/pkg_resources/init.py", line 479, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/usr/local/lib/python2.7/dist-packages/pkg_resources/init.py", line 2703, in load_entry_point
return ep.load()
File "/usr/local/lib/python2.7/dist-packages/pkg_resources/init.py", line 2321, in load
return self.resolve()
File "/usr/local/lib/python2.7/dist-packages/pkg_resources/init.py", line 2327, in resolve
module = import(self.module_name, fromlist=['name'], level=0)
File "/usr/local/lib/python2.7/dist-packages/ryu/cmd/manager.py", line 34, in
from ryu.base.app_manager import AppManager
File "/usr/local/lib/python2.7/dist-packages/ryu/base/app_manager.py", line 37, in
from ryu.controller.controller import Datapath
File "/usr/local/lib/python2.7/dist-packages/ryu/controller/controller.py", line 71, in
help='list of IP address and port pairs (default empty). '
File "/usr/local/lib/python2.7/dist-packages/oslo_config/cfg.py", line 1060, in init
super(ListOpt, self).init(name, type=types.List(), **kwargs)
TypeError: init() got an unexpected keyword argument 'item_type'