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'