title: VSCT menu items not showing
body: <p>Visual Studio 2019 16.5.0 preview 1.</p>
  
  <p>I'm trying to get my menu items to show up either in a group or on a different menu.</p>
  
  <p>Currently the menu items show up in the View/Other Windows menu on visual studio if I point them to IDG_VS_WNDO_OTRWNDWS1, but if I try to point them to MyMenuGroup, they just don't appear.  The code will run but the menu items never show up on the menu.  If I try to point the buttons to IDM_VS_MENU_EXTENSIONS, it won't even compile, giving the error below:</p>
  
  <pre><code>Undefined 'Parent/@id' attribute 'IDM_VS_MENU_EXTENSIONS' in a &lt;Button&gt; element 
  </code></pre>
  
  <p>Below is my code:</p>
  
  <pre><code>&lt;Groups&gt;
    &lt;Group guid="MyGroupMenuSet" id="MyMenuGroup" priority="0x0100"&gt;
      &lt;Parent guid="guidSHLMainMenu" id="IDG_VS_WNDO_OTRWNDWS1" /&gt;
    &lt;/Group&gt;
  &lt;/Groups&gt;
  
  &lt;Buttons&gt;
    &lt;Button guid="My_ExtVS2019PackageCmdSet" id="cmdidMyWindowCommand" priority="0x0100" type="Button"&gt;
      &lt;!-- &lt;Parent guid="guidSHLMainMenu" id="IDG_VS_WNDO_OTRWNDWS1" /&gt; --&gt;
      &lt;Parent guid="MyGroupMenuSet" id="MyMenuGroup" /&gt;
      &lt;Strings&gt;
        &lt;ButtonText&gt;My Main Window&lt;/ButtonText&gt;
      &lt;/Strings&gt;
    &lt;/Button&gt;
    &lt;Button guid="My_ExtVS2019PackageCmdSet" id="cmdidMyOtherControlCommand" priority="0x0100" type="Button"&gt;
      &lt;!--&lt;Parent guid="guidSHLMainMenu" id="IDG_VS_WNDO_OTRWNDWS1" /&gt;--&gt;
      &lt;Parent guid="MyGroupMenuSet" id="MyMenuGroup" /&gt;
      &lt;Strings&gt;
        &lt;ButtonText&gt;My Other Window&lt;/ButtonText&gt;
      &lt;/Strings&gt;
    &lt;/Button&gt;
  &lt;/Buttons&gt;
  &lt;/Commands&gt;
  
  &lt;Symbols&gt;
    &lt;!-- This is the package guid. --&gt;
    &lt;GuidSymbol name="My_ExtVS2019Package" value="{a28e16ed-f550-4cac-b087-f3728834a026}" /&gt;
  
    &lt;GuidSymbol value="{3d62bd83-4a3e-4e04-8ea8-800ea9316e90}" name="My_ExtVS2019PackageCmdSet"&gt;
      &lt;IDSymbol value="256" name="cmdidMyWindowCommand" /&gt;
      &lt;IDSymbol value="257" name="cmdidMyOtherControlCommand" /&gt;
    &lt;/GuidSymbol&gt;
  
    &lt;GuidSymbol value="{dd7dd38d-bf53-408e-baa4-c5c7c7774f19}" name="MyGroupMenuSet"&gt;
      &lt;IDSymbol value="4128" name="MyMenuGroup" /&gt;
      &lt;IDSymbol value="256" name="cmdidCommand1" /&gt;
    &lt;/GuidSymbol&gt;
  
  &lt;/Symbols&gt;
  </code></pre>
  
  <p>Any clue what's wrong with my code?</p>