Поток при котором выбирается файл, приводит к закрытию программы

import sys, random,threading,time 
from ui import Ui_Dialog
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
app = QtWidgets.QApplication(sys.argv)
Form = QtWidgets.QWidget()
ui = Ui_Dialog()
ui.setupUi(Form)
def test():
    fil = QFileDialog.getOpenFileName()
    with open(fil[0], "rb") as file:
        content: bytes = file.read()
    binary: str = "".join(map("{:08b}".format, content))
    print("Процесс успешно закончен")
def pr():
    thr = threading.Thread(target=test)
    thr.start()
ui.pushButton.clicked.connect(pr)
Form.show()
sys.exit(app.exec_())

from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(400, 300)
        self.pushButton = QtWidgets.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(150, 90, 89, 25))
        self.pushButton.setObjectName("pushButton")
        self.lineEdit = QtWidgets.QLineEdit(Dialog)
        self.lineEdit.setGeometry(QtCore.QRect(30, 90, 113, 25))
        self.lineEdit.setObjectName("lineEdit")
        self.checkBox = QtWidgets.QCheckBox(Dialog)
        self.checkBox.setGeometry(QtCore.QRect(160, 150, 92, 23))
        self.checkBox.setObjectName("checkBox")
 
        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)
 
    def retranslateUi(self, Dialog):
        _translate = QtCore.QCoreApplication.translate
        Dialog.setWindowTitle(_translate("Dialog", "test"))
        self.pushButton.setText(_translate("Dialog", "начать"))
        self.checkBox.setText(_translate("Dialog", "CheckBox"))

import sys, random,threading,time # sys нужен для передачи argv в QApplication
from ui import Ui_Dialog
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *
 
app = QtWidgets.QApplication(sys.argv)
Form = QtWidgets.QWidget()
ui = Ui_Dialog()
ui.setupUi(Form)
def test(fil):
    with open(fil[0], "rb") as file:
        content: bytes = file.read()
    binary: str = "".join(map("{:08b}".format, content))
    print("Процесс успешно закончен")
def pr():
    fil = QFileDialog.getOpenFileName()
    thr = threading.Thread(target=test, args=(fil,))
    thr.start()
ui.pushButton.clicked.connect(pr)
Form.show()
 
sys.exit(app.exec_())