Traceback (most recent call last):
  File "electrum\gui\qt\main_window.py", line 129, in onPress
  File "electrum\gui\qt\__init__.py", line 302, in show_network_dialog
  File "electrum\gui\qt\network_dialog.py", line 62, in __init__
  File "electrum\gui\qt\network_dialog.py", line 341, in __init__
  File "electrum\gui\qt\network_dialog.py", line 385, in update
  File "electrum\gui\qt\network_dialog.py", line 160, in update
  File "electrum\blockchain.py", line 250, in get_name
  File "electrum\blockchain.py", line 520, in get_hash
electrum.blockchain.MissingHeader: 828184