title: VBA error 'Wrong number of arguments or invalid property assignments' when running macro via custom button
body: <p>I have a macro that I call via a tab/group/button added by the Custom UI Editor -</p>
  
  <pre><code>&lt;customUI xmlns="http://schemas.microsoft.com/office/2006/01/customui"&gt;
      &lt;ribbon startFromScratch="false"&gt;
          &lt;tabs&gt;
              &lt;tab id="tabCustomActions" label="Custom ActionsXXX" insertAfterMso="TabDeveloper"&gt;
                  &lt;group id="GroupTLA" label="TLA Actions"&gt;
                      &lt;button id="buttonFormatTLA" label="Format as TLA" image="TLALogo" size="large" onAction="start_tla" /&gt;
                  &lt;/group&gt;
              &lt;/tab&gt;
          &lt;/tabs&gt;
      &lt;/ribbon&gt;
  &lt;/customUI&gt;
  </code></pre>
  
  <p>The button shows up just fine, with my custom logo, but when ever I click the button I get the follow error -</p>
  
  <p><img src="https://i.stack.imgur.com/VyGLI.png" alt="VBA Error"></p>
  
  <p>VBA is not opened following this error, as it usually is, and no code within VBA is indicated as the problem if I open the developer console and then try and click the button.</p>
  
  <p>Strangely though, if I try and run the macro manually, it works fine with no errors. Does anybody have any ideas how to solve this?</p>
  
  <p>Here is my full code in a <a href="http://pastebin.com/H3eQ2XXQ" rel="noreferrer">Pastebin</a>, should you wish to view it. Thanks.</p>