fix #4958

electrum/gui/qt/history_list.py

@@ -89,6 +89,7 @@ class HistoryModel(QAbstractItemModel, PrintError):
         self.view = None  # type: HistoryList
         self.transactions = OrderedDictWithIndex()
         self.tx_status_cache = {}  # type: Dict[str, Tuple[int, str]]
+        self.summary = None
 
     def set_view(self, history_list: 'HistoryList'):
         # FIXME HistoryModel and HistoryList mutually depend on each other.