title: Is the htmlunit "WARNING: CSSValue '0\0' has to be a 'px', 'em', '%', 'mm', 'ex', or 'pt' value." really just a warning?
body: <p>I'm trying to load a web page with htmlunit 2.33 and my app displays the above CSS warning in a seemingly endless, repeating list.</p>
  
  <p>I'm specifying FIREFOX_60.</p>
  
  <p>I've tried setting the "silent" css error handler, but that doesn't help.</p>
  
  <pre><code>wc.setCssErrorHandler(new SilentCssErrorHandler());
  </code></pre>
  
  <p>I'm not sure that setting the log level to OFF is the right answer, either.  </p>
  
  <p>It looked to me like the htmlunit library was stuck in a loop.  Sure enough, when I let the page complete, I was presented with this error: </p>
  
  <pre><code>Exception in thread "main" 
  Exception: java.lang.OutOfMemoryError thrown from the        
   UncaughtExceptionHandler in thread "main"
  </code></pre>