title: Shiny apps stops working when ML libraries are imported
body: <p>I´m working on a simple app with an ML model. The app works just fine locally but when I try to deploy it to shiny I get the following error:</p>
  
  <pre><code>Error in value[[3L]](cond) : app.R did not return a shiny.appobj object.
  Calls: local ... tryCatch -&gt; tryCatchList -&gt; tryCatchOne -&gt; &lt;Anonymous&gt;
  Ejecución interrumpida
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/fxMyc.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fxMyc.png" alt="enter image description here"></a></p>
  
  <p>I have updated OR to the latest version (5.2) and installed all packages again. But And still getting the same error. </p>
  
  <p>I try then with the a simpler app and realize that the issue appears when I import either caret or iml libraries, since the icon on the top of the GUI changes and is not reconizing the code as a proper shiny app.</p>
  
  <p><a href="https://i.stack.imgur.com/OYRg0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OYRg0.png" alt="enter image description here"></a></p>
  
  <p>After importing  caret and iml</p>
  
  <p><a href="https://i.stack.imgur.com/eJuo1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eJuo1.png" alt="enter image description here"></a></p>