File "electrum\util.py", line 1036, in run_with_except_hook
  File "threading.py", line 870, in run
  File "electrum\gui\qt\main_window.py", line 2936, in privkeys_thread
  File "electrum\wallet.py", line 573, in export_private_key
  File "electrum\keystore.py", line 261, in get_private_key
  File "electrum\bitcoin.py", line 708, in deserialize_privkey
  File "electrum\ecc.py", line 428, in normalize_secret_bytes