File "/usr/lib/python3/dist-packages/electrum/gui/qt/network_dialog.py", line 73, in on_update
    self.nlayout.update()
  File "/usr/lib/python3/dist-packages/electrum/gui/qt/network_dialog.py", line 349, in update
    self.nodes_list_widget.update(network=self.network,
  File "/usr/lib/python3/dist-packages/electrum/gui/qt/network_dialog.py", line 142, in update
    name = b.get_name()
  File "/usr/lib/python3/dist-packages/electrum/blockchain.py", line 250, in get_name
    return self.get_hash(self.get_max_forkpoint()).lstrip('0')[0:10]
  File "/usr/lib/python3/dist-packages/electrum/blockchain.py", line 517, in get_hash
    header = self.read_header(height)
  File "/usr/lib/python3/dist-packages/electrum/blockchain.py", line 201, in func_wrapper
    return func(self, *args, **kwargs)
  File "/usr/lib/python3/dist-packages/electrum/blockchain.py", line 473, in read_header
    self.assert_headers_file_available(name)
  File "/usr/lib/python3/dist-packages/electrum/blockchain.py", line 437, in assert_headers_file_available
    raise FileNotFoundError('Cannot find headers file but headers_dir is there. Should be at {}'.format(path))