title: SSAS MDX Create set fails with on an empty set
body: <p>I am currently maintaining some legacy MDX code. After some ETL changes in one of the columns I have now only False values - previously there were both True and False values to be found in the [Bool1]. My question is hot to change the below code fragment so that it will not fail with only False values?</p>
  
  <pre><code>CREATE SET CURRENTCUBE.[Set1]
      AS { [Customer].[Bool1].&amp;amp;[True] }, DISPLAY_FOLDER = 'Dimension Filters';
  </code></pre>
  
  <p>The error I am getting is:</p>
  
  <p>The level '&amp;[True]' object was not found in the cube when the string, [Customer].[Bool1].&amp;[True], was parsed.</p>
  
  <p>Maybe there is a reference later to this object and as it is empty it fails?</p>