this is my current wxsmith c++ code, with an error: " it doesn’t show me anything past the sizer. The designer has the Frame, the panel, the sizer and nothing else. it doesn’t show me anything past the sizer. The designer has the Frame, the panel, the sizer and nothing else."

Help me fix it:

<?xml version="1.0" encoding="utf-8" ?>
<wxsmith>
	<object class="wxFrame" name="simple_game_libraryFrame">
    <title>Simple Game Library</title>
    <centered>1</centered>
    <size>960,444</size>
    <bg>wxSYS_COLOUR_HOTLIGHT</bg>
    <minsize>976,485</minsize>
    <maxsize>-1,-1</maxsize>
    <id_arg>0</id_arg>
    <style>wxDEFAULT_FRAME_STYLE|wxTAB_TRAVERSAL</style>
    <object class="wxPanel" name="m_panel1" variable="Panel1" member="yes">
      <pos>-1,-1</pos>
      <size>968,480</size>
      <object class="wxBoxSizer" name="m_sizerPanel" variable="SizerPanel" member="yes">
        <orient>wxVERTICAL</orient>
        <item flag="0">
          <border>5</border>
          <object class="wxChoice" name="m_choiceGenre" variable="ChoiceFilter" member="yes">
            <content>
              <item>System</item>
              <item>Genre</item>
              <item>Start Year</item>
              <item>Completion Status</item>
            </content>
            <size>296,23</size>
          </object>
        </item>
        <item flag="1">
          <border>5</border>
          <object class="wxListBox" name="ID_LISTBOX1" variable="ListBoxFilter" member="yes">
            <default>-1</default>
            <size>296,312</size>
          </object>
        </item>
        <item flag="1">
          <border>5</border>
          <object class="wxSearchCtrl" name="ID_SEARCHCTRL1" variable="SearchCtrlFilter" member="yes">
            <cancel_button>1</cancel_button>
            <size>256,24</size>
          </object>
        </item>
        <item flag="1">
          <border>5</border>
          <object class="wxGridBagSizer" name="m_gridBagSizer" variable="GridBagSizer" member="yes">
            <item flag="1">
              <pos>0,0</pos>
              <object class="wxGrid" name="m_gridGames" variable="GridGames" member="yes">
                <cols>5</cols>
                <readonly>1</readonly>
                <collabels>
                  <item>Name</item>
                  <item>System</item>
                  <item>Genre</item>
                  <item>Start Year</item>
                  <item>Completion Status</item>
                </collabels>
                <minsize>-1,-1</minsize>
                <maxsize>-1,-1</maxsize>
                <style>wxBORDER_SIMPLE|wxVSCROLL|wxHSCROLL</style>
              </object>
            </item>
            <item flag="1">
              <pos>1,0</pos>
              <object class="wxListCtrl" name="ID_LISTCTRL1" variable="ListCtrl1" member="yes">
                <pos>1424,424</pos>
              </object>
            </item>
          </object>
        </item>
        <item flag="1">
          <border>5</border>
          <object class="wxBitmapButton" name="ID_BITMAPBUTTON1" variable="BitmapButtonHamburger" member="yes">
            <bitmap>./res/bars.png</bitmap>
            <size>24,24</size>
          </object>
        </item>
      </object>
    </object>
  </object>
</wxsmith>