Traceback (most recent call last):
  File "electrum\gui\qt\send_tab.py", line 209, in spend_max
  File "electrum\gui\qt\send_tab.py", line 202, in <lambda>
  File "electrum\util.py", line 470, in do_profile
  File "electrum\wallet.py", line 1793, in make_unsigned_transaction
  File "electrum\wallet.py", line 208, in get_locktime_for_new_transaction
  File "electrum\blockchain.py", line 486, in is_tip_stale
  File "electrum\blockchain.py", line 482, in header_at_tip
  File "electrum\util.py", line 1340, in func_wrapper
  File "electrum\blockchain.py", line 472, in read_header
OSError: [Errno 22] Invalid argument