Traceback (most recent call last):
  File "electrum\util.py", line 1073, in run_with_except_hook
  File "threading.py", line 953, in run
  File "electrum\gui\qt\main_window.py", line 2272, in privkeys_thread
  File "electrum\wallet.py", line 815, in export_private_key
  File "electrum\keystore.py", line 308, in get_private_key
  File "electrum\bitcoin.py", line 695, in deserialize_privkey
  File "electrum\ecc.py", line 452, in normalize_secret_bytes
Exception: invalid EC private key scalar: zero