title: knitr doesn't know new function (r-markdown)
body: <p>I have a problem regarding the HTML-output with knitr (r-markdown).</p>
  
  <p>I worked with the function <code>gamlss</code> from the package "gamlss", but <code>knitr</code> cannot find this function/package. So when I try to make an output with "Knit HTML", it just appears an error message: </p>
  
  <blockquote>
    <p>"(error in eval(expr, envir, enclos) :    couldnt find Function
    "gamlss"  Calls:  ... handle -> withCallingHandlers ->
    withVisible -> eval -> eval implementation stopped.  "</p>
  </blockquote>
  
  <p>Has anybody ever dealt with a similar problem? </p>