Ubuntu core 18 crashes during wifi connection during initial configuration

[jagdish gediya]

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Traceback (most recent call last):
  File "/usr/bin/console-conf", line 91, in <module>
    sys.exit(main())
  File "/usr/bin/console-conf", line 88, in main
    interface.run()
  File "/usr/share/subiquity/subiquitycore/core.py", line 152, in run
    self.common['loop'].run()
  File "/usr/lib/python3/dist-packages/urwid/main_loop.py", line 286, in run
    self._run()
  File "/usr/lib/python3/dist-packages/urwid/main_loop.py", line 384, in _run
    self.event_loop.run()
  File "/usr/lib/python3/dist-packages/urwid/main_loop.py", line 788, in run
    self._loop()
  File "/usr/lib/python3/dist-packages/urwid/main_loop.py", line 825, in _loop
    self._watch_files[fd]()
  File "/usr/share/subiquity/subiquitycore/controllers/network.py", line 285, in data_ready
    super().data_ready(fd)
  File "/usr/lib/python3/dist-packages/probert/network.py", line 374, in data_ready
    self._fdmap[fd]()
  File "/usr/share/subiquity/subiquitycore/controllers/network.py", line 264, in route_change
    self.default_route_waiter()
  File "/usr/share/subiquity/subiquitycore/controllers/network.py", line 152, in got_route
    os.write(self.success_w, b'x')
OSError: [Errno 9] Bad file descriptor

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