@Santosh Reddy below is a sample ui.

@ChrisW67 .. I do have a layout for the group-box, as I mentioned in my description the group-box has a grid layout.

by main problem is that the widget in the designer is not the same when i run it.

//mainwindow.ui
Qt Code: 
  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <ui version="4.0">
  3.  <class>MainWindow</class>
  4.  <widget class="QMainWindow" name="MainWindow">
  5.   <property name="geometry">
  6.    <rect>
  7.     <x>0</x>
  8.     <y>0</y>
  9.     <width>498</width>
  10.     <height>523</height>
  11.    </rect>
  12.   </property>
  13.   <property name="windowTitle">
  14.    <string>MainWindow</string>
  15.   </property>
  16.   <widget class="QWidget" name="centralWidget">
  17.    <layout class="QGridLayout" name="gridLayout">
  18.     <item row="1" column="0">
  19.      <widget class="QTabWidget" name="tabWidget">
  20.       <property name="currentIndex">
  21.        <number>0</number>
  22.       </property>
  23.       <widget class="QWidget" name="tab">
  24.        <attribute name="title">
  25.         <string>Tab 1</string>
  26.        </attribute>
  27.        <layout class="QGridLayout" name="gridLayout_11">
  28.         <item row="0" column="0">
  29.          <widget class="QGroupBox" name="groupBox">
  30.           <property name="title">
  31.            <string>Main</string>
  32.           </property>
  33.           <layout class="QGridLayout" name="gridLayout_2">
  34.            <item row="0" column="0">
  35.             <widget class="QScrollArea" name="scrollArea">
  36.              <property name="widgetResizable">
  37.               <bool>true</bool>
  38.              </property>
  39.              <widget class="QWidget" name="scrollAreaWidgetContents">
  40.               <property name="geometry">
  41.                <rect>
  42.                 <x>0</x>
  43.                 <y>0</y>
  44.                 <width>450</width>
  45.                 <height>213</height>
  46.                </rect>
  47.               </property>
  48.               <layout class="QGridLayout" name="gridLayout_5">
  49.                <item row="0" column="0">
  50.                 <widget class="QGroupBox" name="groupBox_2">
  51.                  <property name="minimumSize">
  52.                   <size>
  53.                    <width>0</width>
  54.                    <height>0</height>
  55.                   </size>
  56.                  </property>
  57.                  <property name="maximumSize">
  58.                   <size>
  59.                    <width>5000</width>
  60.                    <height>5000</height>
  61.                   </size>
  62.                  </property>
  63.                  <property name="title">
  64.                   <string>Test</string>
  65.                  </property>
  66.                  <layout class="QGridLayout" name="gridLayout_3">
  67.                   <property name="margin">
  68.                    <number>0</number>
  69.                   </property>
  70.                   <item row="0" column="0">
  71.                    <widget class="QScrollArea" name="scrollArea_2">
  72.                     <property name="widgetResizable">
  73.                      <bool>true</bool>
  74.                     </property>
  75.                     <widget class="QWidget" name="scrollAreaWidgetContents_2">
  76.                      <property name="geometry">
  77.                       <rect>
  78.                        <x>0</x>
  79.                        <y>0</y>
  80.                        <width>221</width>
  81.                        <height>164</height>
  82.                       </rect>
  83.                      </property>
  84.                      <layout class="QGridLayout" name="gridLayout_4">
  85.                       <item row="0" column="0">
  86.                        <widget class="QLabel" name="label">
  87.                         <property name="text">
  88.                          <string>TextLabel</string>
  89.                         </property>
  90.                        </widget>
  91.                       </item>
  92.                       <item row="0" column="1">
  93.                        <widget class="QLineEdit" name="lineEdit"/>
  94.                       </item>
  95.                       <item row="1" column="0">
  96.                        <widget class="QLabel" name="label_2">
  97.                         <property name="text">
  98.                          <string>TextLabel</string>
  99.                         </property>
  100.                        </widget>
  101.                       </item>
  102.                       <item row="1" column="1">
  103.                        <widget class="QLineEdit" name="lineEdit_2"/>
  104.                       </item>
  105.                       <item row="2" column="0">
  106.                        <widget class="QLabel" name="label_3">
  107.                         <property name="text">
  108.                          <string>TextLabel</string>
  109.                         </property>
  110.                        </widget>
  111.                       </item>
  112.                       <item row="2" column="1">
  113.                        <widget class="QLineEdit" name="lineEdit_3"/>
  114.                       </item>
  115.                       <item row="3" column="0">
  116.                        <widget class="QLabel" name="label_4">
  117.                         <property name="text">
  118.                          <string>TextLabel</string>
  119.                         </property>
  120.                        </widget>
  121.                       </item>
  122.                       <item row="3" column="1">
  123.                        <widget class="QLineEdit" name="lineEdit_4"/>
  124.                       </item>
  125.                      </layout>
  126.                     </widget>
  127.                    </widget>
  128.                   </item>
  129.                  </layout>
  130.                 </widget>
  131.                </item>
  132.                <item row="0" column="1">
  133.                 <spacer name="horizontalSpacer_2">
  134.                  <property name="orientation">
  135.                   <enum>Qt::Horizontal</enum>
  136.                  </property>
  137.                  <property name="sizeHint" stdset="0">
  138.                   <size>
  139.                    <width>40</width>
  140.                    <height>20</height>
  141.                   </size>
  142.                  </property>
  143.                 </spacer>
  144.                </item>
  145.               </layout>
  146.              </widget>
  147.             </widget>
  148.            </item>
  149.            <item row="1" column="0">
  150.             <spacer name="verticalSpacer">
  151.              <property name="orientation">
  152.               <enum>Qt::Vertical</enum>
  153.              </property>
  154.              <property name="sizeHint" stdset="0">
  155.               <size>
  156.                <width>20</width>
  157.                <height>40</height>
  158.               </size>
  159.              </property>
  160.             </spacer>
  161.            </item>
  162.           </layout>
  163.          </widget>
  164.         </item>
  165.        </layout>
  166.       </widget>
  167.      </widget>
  168.     </item>
  169.    </layout>
  170.   </widget>
  171.   <widget class="QMenuBar" name="menuBar">
  172.    <property name="geometry">
  173.     <rect>
  174.      <x>0</x>
  175.      <y>0</y>
  176.      <width>498</width>
  177.      <height>23</height>
  178.     </rect>
  179.    </property>
  180.   </widget>
  181.   <widget class="QToolBar" name="mainToolBar">
  182.    <attribute name="toolBarArea">
  183.     <enum>TopToolBarArea</enum>
  184.    </attribute>
  185.    <attribute name="toolBarBreak">
  186.     <bool>false</bool>
  187.    </attribute>
  188.   </widget>
  189.   <widget class="QStatusBar" name="statusBar"/>
  190.  </widget>
  191.  <layoutdefault spacing="6" margin="11"/>
  192.  <resources/>
  193.  <connections/>
  194. </ui>
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