PyQt5 Multithreading Crashes with No Console Error

I have a project I am working on for work. Due to the nature of the project I cant share all of the code.

Below is the code of me trying to implement a thread on button click.

from PyQt5 import QtCore, QtWidgets, QtGui, QtSerialPort
from PyQt5 import uic
import sys, time

class BETA_THREADED(QtWidgets.QMainWindow):
    def __init__(self):
        QtWidgets.QMainWindow.__init__(self)
        self.ui = uic.loadUi('rocket_3.ui', self)
        # self.resize(1920, 1080)

        self.thread={}
        self.launchButton.clicked.connect(self.start_worker)
        self.abortButton.clicked.connect(self.stop_worker)

    def start_worker(self):
        print('1')
        self.thread[1] = ThreadClass(parent = None, index = 1)
        self.thread[1].start()
        self.thread[1].any_signal.connect(self.launchSequence)
        self.launchButton.setEnabled(False)

    def stop_worker(self):
        self.thread[1].stop()
        self.launchButton.setEnabled(True)

    def launchSequence(self):
        print('Test')

class ThreadClass(QtCore.QThread):
    
    any_signal = QtCore.pyqtSignal(int)
    def __init__(self, parent=None,index=0):
        super(ThreadClass, self).__init__(parent)
        self.index=index
        self.is_running = True
    def run(self):
        print('Starting thread...',self.index)
        cnt=0
        while (True):
            cnt+=1
            if cnt==99: cnt=0
            time.sleep(0.01)
            self.any_signal.emit(cnt) 
    def stop(self):
        self.is_running = False
        print('Stopping thread...',self.index)
        self.terminate()

app = QtWidgets.QApplication(sys.argv)
mainWindow = BETA_THREADED()
mainWindow.show()
sys.exit(app.exec_())

The UI file is generated by PyQt Designer, and the buttons are regular push buttons.

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Rocket</class>
 <widget class="QMainWindow" name="Rocket">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>1262</width>
    <height>323</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Rocket</string>
  </property>
  <property name="styleSheet">
   <string notr="true"/>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QTextBrowser" name="statusBar">
    <property name="geometry">
     <rect>
      <x>230</x>
      <y>220</y>
      <width>1011</width>
      <height>61</height>
     </rect>
    </property>
   </widget>
   <widget class="QLabel" name="label_6">
    <property name="geometry">
     <rect>
      <x>230</x>
      <y>190</y>
      <width>111</width>
      <height>17</height>
     </rect>
    </property>
    <property name="font">
     <font>
      <family>Carlito</family>
      <pointsize>14</pointsize>
     </font>
    </property>
    <property name="text">
     <string>STATUS</string>
    </property>
   </widget>
   <widget class="QGroupBox" name="groupBox">
    <property name="enabled">
     <bool>true</bool>
    </property>
    <property name="geometry">
     <rect>
      <x>-10</x>
      <y>-10</y>
      <width>221</width>
      <height>291</height>
     </rect>
    </property>
    <property name="title">
     <string/>
    </property>
    <property name="flat">
     <bool>false</bool>
    </property>
    <property name="checkable">
     <bool>false</bool>
    </property>
    <widget class="QPushButton" name="launchButton">
     <property name="geometry">
      <rect>
       <x>30</x>
       <y>60</y>
       <width>161</width>
       <height>101</height>
      </rect>
     </property>
     <property name="font">
      <font>
       <family>Carlito</family>
       <pointsize>14</pointsize>
      </font>
     </property>
     <property name="styleSheet">
      <string notr="true">background-color: blue;</string>
     </property>
     <property name="text">
      <string>LAUNCH</string>
     </property>
    </widget>
    <widget class="QPushButton" name="abortButton">
     <property name="geometry">
      <rect>
       <x>30</x>
       <y>180</y>
       <width>161</width>
       <height>101</height>
      </rect>
     </property>
     <property name="font">
      <font>
       <family>Carlito</family>
       <pointsize>14</pointsize>
      </font>
     </property>
     <property name="styleSheet">
      <string notr="true">background-color: red;</string>
     </property>
     <property name="text">
      <string>ABORT</string>
     </property>
    </widget>
   </widget>
  </widget>
 </widget>
 <tabstops>
  <tabstop>launchButton</tabstop>
  <tabstop>statusBar</tabstop>
  <tabstop>abortButton</tabstop>
 </tabstops>
 <resources/>
 <connections>
  <connection>
   <sender>launchButton</sender>
   <signal>clicked()</signal>
   <receiver>launchButton</receiver>
   <slot>click()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>546</x>
     <y>720</y>
    </hint>
    <hint type="destinationlabel">
     <x>546</x>
     <y>720</y>
    </hint>
   </hints>
  </connection>
  <connection>
   <sender>abortButton</sender>
   <signal>clicked()</signal>
   <receiver>abortButton</receiver>
   <slot>click()</slot>
   <hints>
    <hint type="sourcelabel">
     <x>630</x>
     <y>910</y>
    </hint>
    <hint type="destinationlabel">
     <x>630</x>
     <y>910</y>
    </hint>
   </hints>
  </connection>
 </connections>
</ui>

When I run the file my window opens as expected and then closes on any button click. I cannot for the life of me figure out why.

Edit: Corrected the spelling and other error noted, provided the full file for both python and UI. The program still closes on any button click with no error in cmd.