Traceback (most recent call last):
  File "electrum/gui/qt/my_treeview.py", line 458, in showEvent
  File "electrum/gui/qt/history_list.py", line 523, in update
  File "electrum/util.py", line 470, in do_profile
  File "electrum/gui/qt/history_list.py", line 280, in refresh
  File "electrum/util.py", line 470, in do_profile
  File "electrum/wallet.py", line 1240, in get_full_history
  File "electrum/wallet.py", line 1044, in get_onchain_history
  File "electrum/util.py", line 1340, in func_wrapper
  File "electrum/address_synchronizer.py", line 103, in func_wrapper
  File "electrum/address_synchronizer.py", line 518, in f
  File "electrum/address_synchronizer.py", line 555, in get_history
  File "electrum/util.py", line 1340, in func_wrapper
  File "electrum/address_synchronizer.py", line 103, in func_wrapper
  File "electrum/address_synchronizer.py", line 518, in f
  File "electrum/address_synchronizer.py", line 855, in get_balance
TypeError: sequence item 0: expected str instance, NoneType found