File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/gui/qt/network_dialog.py", line 468, in set_server
    self.network.run_from_another_thread(self.network.set_parameters(net_params))
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/network.py", line 299, in run_from_another_thread
    return fut.result()
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/concurrent/futures/_base.py", line 432, in result
    return self.__get_result()
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/concurrent/futures/_base.py", line 384, in __get_result
    raise self._exception
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/util.py", line 934, in wrapper
    return await func(*args, **kwargs)
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/network.py", line 617, in set_parameters
    await self.switch_lagging_interface()
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/network.py", line 635, in switch_lagging_interface
    best_header = self.blockchain().read_header(self.get_local_height())
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/blockchain.py", line 186, in func_wrapper
    return func(self, *args, **kwargs)
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/blockchain.py", line 457, in read_header
    self.assert_headers_file_available(name)
  File "/tmp/.mount_electrLMoFh1/usr/lib/python3.6/site-packages/electrum/blockchain.py", line 421, in assert_headers_file_available
    raise FileNotFoundError('Cannot find headers file but headers_dir is there. Should be at {}'.format(path))