title: Errors when build unity proejct for Macos on Windows
body: <p>When I want to build a macOS version of my Unity project, I get following errors. But When I choose to Build Winows Version, it goes very well. Can someone help with this problem?</p>
  <p>Many Thanks.</p>
  <p>My version of Unity package is 2020.3.18f1c1 and my computer is Windows</p>
  <p><a href="https://i.stack.imgur.com/Ex7Wb.png" rel="nofollow noreferrer">enter image description here</a></p>
  <pre><code>Library\PackageCache\com.unity.ugui@1.0.0\Runtime\UI\Core\Image.cs(873,87): error CS1061: 'Sprite' does not contain a definition for 'isUsingPlaceholder' and no accessible extension method 'isUsingPlaceholder' accepting a first argument of type 'Sprite' could be found (are you missing a using directive or an assembly reference?)
  
  Library\PackageCache\com.unity.ugui@1.0.0\Runtime\UI\Core\Image.cs(1851,38): error CS1061: 'SpriteAtlas' does not contain a definition for 'IsPlaceholder' and no accessible extension method 'IsPlaceholder' accepting a first argument of type 'SpriteAtlas' could be found (are you missing a using directive or an assembly reference?)
  </code></pre>