title: My Excel VBA conditional formatting (background color) isn't updating
body: <p>I have an application which opens an Excel workbook and in this workbook there is a sheet which has some cells with conditional formatting (background in red when 1, orange when 2 etc ...).</p>
  
  <p>When there are no values in these cells and I then choose a value from a combobox, it should change the background color but it doesn't. However, when I copy and paste a value from another cell (with conditional formatting), the background color is updated and I have the same problem afterwards (background color doesn't update when I change values).</p>
  
  <p>So I want to create a macro in VBA which allows this update when I change values.</p>
  
  <p>N.B. There are protected cells in the workbook but no protection on these cells. 
  N.B.2: There are 4 cells with the right background color but they are filled before or during Excel opening (it's not my application).</p>
  
  <pre><code>Application.ScreenUpdating = True 'not working
  Application.Calculate             'not working too
  </code></pre>
  
  <p>another weird thing : if i copy/paste all the values (1,2,3,4) from a cell to another + a ctrl + z, then the conditional formatting works fine for all the cells ...</p>