title: R obj must be a foreach object error after update
body: <p>I've been using R's <code>doParallel</code> and <code>foreach</code> package. I updated R and these packages recently (not sure if related to this issue) and noticed this error:</p>
  
  <pre><code>&gt; foreach(a=1:3, b=rep(10, 3)) %do% (a + b)
  Error in e$fun(obj, substitute(ex), parent.frame(), e$data) : 
    obj must be a foreach object
  </code></pre>
  
  <p>The example is one from the <code>foreach</code> vignette. Whats the issue? </p>
  
  <p><s>EDIT:</p>
  
  <p>Started up new R session, re-installed <code>doParallel</code> and issue went away. </s></p>