title: Error "cannot open the connection" in executing "knit HTML" in RStudio
body: <p>I am getting the below error when trying to "knit HTML" in RStudio. </p>
  
  <pre><code>  |................................                                 |  50%
    ordinary text without R code
  
    |.................................................................| 100%
  
  
  processing file: Preview-b0c112a265.Rmd
  label: unnamed-chunk-1
  
  Quitting from lines 16-26 (Preview-b0c112a265.Rmd) 
  Error in file(file, "rt") : cannot open the connection
  Calls: &lt;Anonymous&gt; ... withVisible -&gt; eval -&gt; eval -&gt; read.csv -&gt; read.table -&gt; file
  Execution halted
  </code></pre>
  
  <p>I am using RStudio on a 64-bit win8 machine.</p>