title: Knitr wont compile PDF: "Error in tools::file_path_as_absolute(output_file)"
body: <p>I have created a report in markdown and use the function <code>render()</code> to compile the code into a PDF. It worked fine a month ago, but when I run the code now, it gives me an error:</p>
  
  <blockquote>
    <p>Latexmk: This is Latexmk, John Collins, 22 April 2016, version: 4.45.
    Output created: output/Medborgerskabstabeller99.pdf</p>
    
    <p>Error in tools::file_path_as_absolute(output_file) : 
    file 'output/Medborgerskabstabeller99.pdf' does not exist</p>
  </blockquote>
  
  <p>The render command I use to create the PDF looks like this:</p>
  
  <pre><code>outfile &lt;- file.path("output",paste0("Medborgerskabstabeller99"))
  render(input = "Medborgerskabstabeller.Rmd",
         encoding = "UTF-8",
         output_file = paste0(outfile,".pdf"))
  </code></pre>
  
  <p>First of all, the "Latexmk"-message before did not appear when the code worked.</p>
  
  <p>Second, I have no clue why it says that "Medborgerskabstabeller99.pdf" doesn't exist, when it says above that it just created the file.</p>
  
  <p>Any suggestions on the problem will be highly appreciated!</p>