Yum Update not working

 yum update
Traceback (most recent call last):
  File "/usr/bin/yum", line 58, in <module>
    main.user_main(sys.argv[1:], exit_code=True)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 201, in user_main
    errcode = main(args)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 67, in main
    return _main(base, args, cli_class, option_parser_class)
  File "/usr/lib/python3.6/site-packages/dnf/cli/main.py", line 102, in _main
    cli.configure(list(map(ucd, args)), option_parser())
  File "/usr/lib/python3.6/site-packages/dnf/cli/cli.py", line 830, in configure
    self.base.init_plugins(opts.disableplugin, opts.enableplugin, self)
  File "/usr/lib/python3.6/site-packages/dnf/base.py", line 307, in init_plugins
    self._plugins._run_init(self, cli)
  File "/usr/lib/python3.6/site-packages/dnf/plugin.py", line 154, in _run_init
    plugin = p_cls(base, cli)
  File "/usr/lib/python3.6/site-packages/dnf-plugins/spacewalk.py", line 79, in __init__
    self.activate_channels()
  File "/usr/lib/python3.6/site-packages/dnf-plugins/spacewalk.py", line 109, in activate_channels
    login_info = up2date_client.up2dateAuth.getLoginInfo(timeout=self.conf.timeout)
  File "/usr/lib/python3.6/site-packages/up2date_client/up2dateAuth.py", line 231, in getLoginInfo
    login(timeout=timeout)
  File "/usr/lib/python3.6/site-packages/up2date_client/up2dateAuth.py", line 198, in login
    li = server.up2date.login(systemId, socket.getfqdn())
  File "/usr/lib/python3.6/site-packages/up2date_client/rhnserver.py", line 67, in __call__
    return rpcServer.doCall(method, *args, **kwargs)
  File "/usr/lib/python3.6/site-packages/up2date_client/rpcServer.py", line 222, in doCall
    ret = method(*args, **kwargs)
  File "/usr/lib64/python3.6/xmlrpc/client.py", line 1112, in __call__
    return self.__send(self.__name, args)
  File "/usr/lib/python3.6/site-packages/up2date_client/rpcServer.py", line 48, in _request1
    ret = self._request(methodname, params)
  File "/usr/lib/python3.6/site-packages/rhn/rpclib.py", line 394, in _request
    self._handler, request, verbose=self._verbose)
  File "/usr/lib/python3.6/site-packages/rhn/transports.py", line 194, in request
    return self._process_response(fd, connection)
  File "/usr/lib/python3.6/site-packages/rhn/transports.py", line 222, in _process_response
    return self.parse_response(fd)
  File "/usr/lib/python3.6/site-packages/rhn/transports.py", line 245, in parse_response
    p.close()
  File "/usr/lib64/python3.6/xmlrpc/client.py", line 448, in close
    parser.Parse(b"", True) # end of data
xml.parsers.expat.ExpatError: syntax error: line 1, column 0