File "electrum\gui\qt\main_window.py", line 3073, in closeEvent
  File "electrum\gui\qt\main_window.py", line 3090, in clean_up
  File "electrum\gui\qt\__init__.py", line 266, in close_window
  File "electrum\daemon.py", line 265, in stop_wallet
  File "electrum\address_synchronizer.py", line 168, in stop_threads
  File "electrum\util.py", line 354, in <lambda>
  File "electrum\util.py", line 350, in do_profile
  File "electrum\storage.py", line 107, in write
  File "electrum\storage.py", line 119, in _write