title: Error in conditional formatting formula where the same formula works in a cell
body: <p>I'm trying to conditionally format a column of cells based on whether the combination of two other columns appear in a Table.</p>
  <p>Here is a link to the test workbook I am playing with and screenshots below for those that don't like clicking strangers links!</p>
  <p><a href="https://1drv.ms/x/s!Al1Kq21dFT1ij4ktFd0mzBniNX00tQ?e=L6aQm4" rel="nofollow noreferrer">https://1drv.ms/x/s!Al1Kq21dFT1ij4ktFd0mzBniNX00tQ?e=L6aQm4</a></p>
  <p><a href="https://i.stack.imgur.com/6MPAI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6MPAI.png" alt="enter image description here" /></a></p>
  <p>On the far left is an Excel table ([Table1]) that contains a list of valid combinations of [Category] and [Item]</p>
  <ul>
  <li>Columns E&amp;F contain some sample data to test against</li>
  <li>Column G is the number of matching combinations I expect to return from a COUNTIFS() function</li>
  <li>Column H is simply the same formula compared to <code>0</code> so I get a boolean result.</li>
  <li>The actual formula to get the result shown in Column H is
  <code>=COUNTIFS(Table1[Category],&quot;=&quot;&amp;E4, Table1[Item],&quot;=&quot;&amp;F4)=0</code></li>
  </ul>
  <p>All the above works as expected.</p>
  <p>In Column J is just some literal text with conditional formatting. The condition is simply <code>=H4</code>, again this works as expected.</p>
  <p>Now to the problem...
  I want to avoid having the helper column (H) so I thought I could just use the same formula that I used in column H, as my condition formula.</p>
  <p>So, I tried to use this in the conditional formatting formula dialog.</p>
  <pre><code>=COUNTIFS(Table1[Category],&quot;=&quot;&amp;E4, Table1[Item],&quot;=&quot;&amp;F4)=0
  </code></pre>
  <p>and with parantheses</p>
  <pre><code>=(COUNTIFS(Table1[Category],&quot;=&quot;&amp;E4, Table1[Item],&quot;=&quot;&amp;F4)=0)
  </code></pre>
  <p><a href="https://i.stack.imgur.com/eQzYf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eQzYf.png" alt="enter image description here" /></a></p>
  <p>Unfortunately, this results in the generic &quot;There's a problem with this formula&quot; error message.</p>
  <p>If might be that there are some limitations with conditional formatting formulae that I'm not aware of (I'm no Excel guru, I'm a SQL developer really).</p>
  <p><em>BTW: I need to stick with using a table as my real-world scenario is that there will be several tables, all populated from a database via a separate process with lengths varying from 2 or 3 entries to potentially thousands.</em></p>
  <p>I would appreciate any help, even if it's just to say &quot;You can't do this, you'll need to use your helper column...&quot;</p>
  <p>Thanks for looking...</p>