Как я могу снять флажок с элемента при нажатии кнопки в древовидном виджете PYQT5?

Я строю древовидную структуру с помощью виджета дерева, и все элементы проверяются по умолчанию. Там есть список, сохраняющий некоторые элементы, которые должны быть сняты. Что я хочу сделать, так это снять флажки с этих элементов при нажатии кнопки. Я могу использовать findItems(uncheckitems, Qt.MatchExactly | Qt.MatchRecursive, 0), чтобы найти объект. Но когда я использую setCheckState(0, Qt.Unchecked), программа всегда падает.

MENUS = [
("Action1", [
    ("Action4", [
        ("Action8", []), ("Action9", []), ("Action10", [])
        ]),
    ("Action6", [
        ("Action11", []), ("Action12", []), ("Action13", [])
        ]),
    ("Action7", [
        ("Action14", []), ("Action15", []), ("Action16", [])
        ]),
    ]),
("Action2", [
    ("Action17", [
        ("Action20", [
            ("Action25", []), ("Action26", []), ("Action27", [])
            ]),
        ("Action21", []),
        ("Action22", []),
        ]),
    ("Action18", [
        ("Action23", [
            ("Action28", []), ("Action29", []), ("Action30", [])
            ]),
        ("Action24", []),
        ]),
    ("Action19", []),
    ]),
("Action3", [
    ("Action31", [
        ("Action34", []), ("Action35", []), ("Action36", [])
        ]),
    ("Action32", [
        ("Action37", []), ("Action38", []), ("Action39", [])
        ]),
    ("Action33", []),
    ]),
]

uncheckedaction = ["Action3", "Action11", "Action29"]

from uitest import Ui_MainWindow
from PyQt5.QtWidgets import (
    QApplication, QMainWindow, QTreeWidgetItem,
    )
from PyQt5.QtCore import Qt

class window(QMainWindow):
    def __init__(self, parent=None):
        super(window, self).__init__(parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.loadMenus(MENUS)
        self.ui.Menutree.itemChanged.connect(self.handleItemChanged)
        self.ui.Uncheck.clicked.connect(self.uncheckprocess)

    def uncheckprocess(self):
        menutree = self.ui.Menutree
        for uncheck in uncheckedaction:
            uncheckeditem = menutree.findItems(uncheck, Qt.MatchExactly | Qt.MatchRecursive, 0)
            print("uncheckeditem:", uncheckeditem)
            uncheckeditem.setCheckState(0, Qt.Unchecked)

    def loadMenus(self, menus):
        def recurse(parent, items):
            for text, children in items:
                item = QTreeWidgetItem(parent)
                item.setText(0, text)
                item.setCheckState(0, Qt.Checked)
                recurse(item, children)
        recurse(self.ui.Menutree, menus)
        self.ui.Menutree.expandAll()

    def handleItemChanged(self, item, column):
        def recurse(parent, state):
            for index in range(parent.childCount()):
                child = parent.child(index)
                # child.setCheckState(0, state)
                child.setDisabled(state == Qt.Unchecked)
                recurse(child, state)
        recurse(item, item.checkState(0))

if __name__ == "__main__":

    app = QApplication([''])
    gui = window()
    gui.show()
    app.exec_()

UI:

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(816, 577)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName("gridLayout")
        self.scrollArea = QtWidgets.QScrollArea(self.centralwidget)
        self.scrollArea.setWidgetResizable(True)
        self.scrollArea.setObjectName("scrollArea")
        self.scrollAreaWidgetContents = QtWidgets.QWidget()
        self.scrollAreaWidgetContents.setGeometry(QtCore.QRect(0, 0, 796, 468))
        self.scrollAreaWidgetContents.setObjectName("scrollAreaWidgetContents")
        self.verticalLayout = QtWidgets.QVBoxLayout(self.scrollAreaWidgetContents)
        self.verticalLayout.setContentsMargins(0, 0, 0, 0)
        self.verticalLayout.setObjectName("verticalLayout")
        self.Menutree = QtWidgets.QTreeWidget(self.scrollAreaWidgetContents)
        self.Menutree.setObjectName("Menutree")
        self.Menutree.headerItem().setText(0, "1")
        self.Menutree.header().setVisible(False)
        self.verticalLayout.addWidget(self.Menutree)
        spacerItem = QtWidgets.QSpacerItem(20, 10, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Minimum)
        self.verticalLayout.addItem(spacerItem)
        self.groupBox = QtWidgets.QGroupBox(self.scrollAreaWidgetContents)
        self.groupBox.setTitle("")
        self.groupBox.setObjectName("groupBox")
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.groupBox)
        self.horizontalLayout.setObjectName("horizontalLayout")
        spacerItem1 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem1)
        self.Previous = QtWidgets.QPushButton(self.groupBox)
        font = QtGui.QFont()
        font.setPointSize(14)
        font.setBold(True)
        font.setWeight(75)
        self.Previous.setFont(font)
        self.Previous.setObjectName("Previous")
        self.horizontalLayout.addWidget(self.Previous)
        spacerItem2 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem2)
        self.Uncheck = QtWidgets.QPushButton(self.groupBox)
        self.Uncheck.setObjectName("Uncheck")
        self.horizontalLayout.addWidget(self.Uncheck)
        spacerItem3 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem3)
        self.Next = QtWidgets.QPushButton(self.groupBox)
        font = QtGui.QFont()
        font.setPointSize(14)
        font.setBold(True)
        font.setWeight(75)
        self.Next.setFont(font)
        self.Next.setObjectName("Next")
        self.horizontalLayout.addWidget(self.Next)
        spacerItem4 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem4)
        self.Next_Save = QtWidgets.QPushButton(self.groupBox)
        font = QtGui.QFont()
        font.setPointSize(14)
        font.setBold(True)
        font.setWeight(75)
        self.Next_Save.setFont(font)
        self.Next_Save.setObjectName("Next_Save")
        self.horizontalLayout.addWidget(self.Next_Save)
        spacerItem5 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem5)
        self.verticalLayout.addWidget(self.groupBox)
        self.scrollArea.setWidget(self.scrollAreaWidgetContents)
        self.gridLayout.addWidget(self.scrollArea, 0, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 816, 21))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.TBlevel1 = QtWidgets.QToolBar(MainWindow)
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Preferred)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.TBlevel1.sizePolicy().hasHeightForWidth())
        self.TBlevel1.setSizePolicy(sizePolicy)
        font = QtGui.QFont()
        font.setPointSize(14)
        self.TBlevel1.setFont(font)
        self.TBlevel1.setObjectName("TBlevel1")
        MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.TBlevel1)
        self.TBlevel2 = QtWidgets.QToolBar(MainWindow)
        font = QtGui.QFont()
        font.setPointSize(12)
        self.TBlevel2.setFont(font)
        self.TBlevel2.setObjectName("TBlevel2")
        MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.TBlevel2)
        MainWindow.insertToolBarBreak(self.TBlevel2)
        self.TBlevel3 = QtWidgets.QToolBar(MainWindow)
        font = QtGui.QFont()
        font.setPointSize(10)
        self.TBlevel3.setFont(font)
        self.TBlevel3.setObjectName("TBlevel3")
        MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.TBlevel3)
        MainWindow.insertToolBarBreak(self.TBlevel3)
        self.TBlevel4 = QtWidgets.QToolBar(MainWindow)
        self.TBlevel4.setObjectName("TBlevel4")
        MainWindow.addToolBar(QtCore.Qt.TopToolBarArea, self.TBlevel4)
        MainWindow.insertToolBarBreak(self.TBlevel4)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.Previous.setText(_translate("MainWindow", "Previous"))
        self.Uncheck.setText(_translate("MainWindow", "Uncheck"))
        self.Next.setText(_translate("MainWindow", "Next"))
        self.Next_Save.setText(_translate("MainWindow", "Next and Save"))
        self.TBlevel1.setWindowTitle(_translate("MainWindow", "toolBar"))
        self.TBlevel2.setWindowTitle(_translate("MainWindow", "toolBar"))
        self.TBlevel3.setWindowTitle(_translate("MainWindow", "toolBar_2"))
        self.TBlevel4.setWindowTitle(_translate("MainWindow", "toolBar"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

Кто-нибудь может мне помочь? Большое спасибо.