File "/usr/lib/python3/dist-packages/electrum/gui/qt/network_dialog.py", line 394, in set_server
    self.network.run_from_another_thread(self.network.set_parameters(net_params))
  File "/usr/lib/python3/dist-packages/electrum/network.py", line 374, in run_from_another_thread
    return fut.result(timeout)
  File "/usr/lib/python3.9/concurrent/futures/_base.py", line 440, in result
    return self.__get_result()
  File "/usr/lib/python3.9/concurrent/futures/_base.py", line 389, in __get_result
    raise self._exception
  File "/usr/lib/python3/dist-packages/electrum/util.py", line 1056, in wrapper
    return await func(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/electrum/network.py", line 618, in set_parameters
    await self.switch_lagging_interface()
  File "/usr/lib/python3/dist-packages/electrum/network.py", line 637, in switch_lagging_interface
    best_header = self.blockchain().header_at_tip()
  File "/usr/lib/python3/dist-packages/electrum/blockchain.py", line 486, in header_at_tip
    return 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 478, in read_header
    raise Exception('Expected to read a full header. This was only {} bytes'.format(len(h)))