title: "Error: lexical error: invalid char in json text" with the IMFData package
body: <p>I have been trying the use the IMFData package but I keep having the same problem. The only thing I've written so far is this:</p>
  
  <pre><code>library(IMFData)
  
  FMI &lt;- DataflowMethod()
  </code></pre>
  
  <p>But I keep receiving this error: </p>
  
  <pre><code>Error: lexical error: invalid char in json text.
                                     &lt;?xml version="1.0" encoding="u
                   (right here) ------^ 
  5.parse_string(txt, bigint_as_char) 
  4.parseJSON(txt, bigint_as_char) 
  3.fromJSON_string(txt = txt, simplifyVector = simplifyVector,simplifyDataFrame = simplifyDataFrame, simplifyMatrix = simplifyMatrix, flatten = flatten, ...) 
  2.jsonlite::fromJSON(httr::content(r, "text")) at IMFData.R#28
  1.DataflowMethod() 
  </code></pre>
  
  <p>I understand that my problem is with json and I've seen many other people having similar errors, but I don't haven't found a solution to mine. Can someone please help me?</p>