Traceback (most recent call last):
  File "electrum/gui/qt/history_list.py", line 774, in <lambda>
  File "electrum/gui/qt/main_window.py", line 2656, in dscancel_dialog
  File "electrum/gui/qt/rbf_dialog.py", line 174, in __init__
  File "electrum/gui/qt/rbf_dialog.py", line 41, in __init__
TypeError: unsupported operand type(s) for /: 'NoneType' and 'int'