File "electrum\gui\qt\main_window.py", line 125, in onPress
  File "electrum\gui\qt\__init__.py", line 229, in show_network_dialog
  File "electrum\gui\qt\network_dialog.py", line 60, in __init__
  File "electrum\gui\qt\network_dialog.py", line 309, in __init__
  File "electrum\gui\qt\network_dialog.py", line 342, in update
  File "electrum\blockchain.py", line 250, in get_name
  File "electrum\blockchain.py", line 517, in get_hash
  File "electrum\blockchain.py", line 201, in func_wrapper
  File "electrum\blockchain.py", line 478, in read_header