title: Add-In XML script keeps disappearing after save
body: <p>I am using the UI Custom Editor to write xml to create a custom ribbon for Excel.  It was working fine; however, suddenly the custom tab disappeared from excel and after checking the script in the editor, I noticed it disappeared.  I tried to reinsert the script and save it, yet it continues to disappear.  I'm so confused.  Can anyone provide information as to what's going on and how I might resolve it?</p>
  
  <pre><code>&lt;customUI xmlns="http://schemas.microsoft.com/office/2009/07/customui"&gt;
  &lt;ribbon&gt;
  &lt;tabs&gt;
  &lt;tab id="USMCAnalysttab" label="USMC Analyst" &gt;
  &lt;group id="group1" label="Range Editing"&gt;
  &lt;button id="button1" label="Recreate NIIN" imageMso="HappyFace" onAction="'USMC Add In.XLAM'!NIIN_Fix" /&gt;
  &lt;button id="button2" label="Insert Decimal" imageMso="OutlookGlobe" onAction="Macro2"
  /&gt;
  &lt;/group&gt;
  &lt;group id="group2" label="Data Extraction"&gt;
  &lt;button id="button3" label="Extract AAC"  imageMso="HappyFace"
  onAction="'USMC Add In.XLAM'AAC_Extraction" /&gt;
  &lt;button id="button4" label="Extract Julian Date" imageMso="OutlookGlobe"
  onAction="'USMC Add In.XLAM'JD_Extraction" /&gt;
  &lt;/group&gt;
  &lt;/tab&gt;
  &lt;/tabs&gt;
  &lt;/ribbon&gt;
  &lt;/customUI&gt;
  </code></pre>