title: Rstudio will not write "UTF-8" encoding with emoji data all of a sudden
body: <p>I am working on a project that uses text files with emojis and I started having issue with writing a dataframe of emojis to a csv file. I have working with these files for some time now and so far I've been able to save the text data  using write.csv(x, "filename") and viewing them with read.csv("filename", encoding = "UTF-8") without any problems. Yesterday, quite suddenly, that stopped working. All the files that I previously saved will still display emojis using the read.csv() function but I can not write and read any new files. For example, if I have:</p>
  
  <pre><code>x &lt;- c("","","")
  View(x)
  write.csv(x, "testemoji.csv")
  x2 &lt;- read.csv("testemoji.csv", encoding = "UTF-8")
  View(x2)
  </code></pre>
  
  <p>x will be</p>
  
  <p><img src="https://i.stack.imgur.com/ctuO6.png" alt="viewed as this"></p>
  
  <p>while x2 will be</p>
  
  <p><img src="https://i.stack.imgur.com/QyPmT.png" alt="viewed as this"></p>
  
  <p>I am using R verion 3.6.3 and windows 10. </p>
  
  <p>What I have tried so far:</p>
  
  <pre><code>write.csv(x, "filename", fileEncoding = "UTF-8")
  
  write.table(x, "filename", fileEncoding = "UTF-8")
  
  write.csv2(x, "filename", fileEncoding = "UTF-8")
  x2&lt;- read.csv2("filename", encoding = "UTF-8")
  </code></pre>
  
  <p>I've tried every option of "tools - global options - coding - saving - default text encoding"</p>
  
  <p>I've also tried messing with the locale language on the computer and the beta-UTF-8 option</p>
  
  <p>when I check the encoding with <code>Encoding(x$v1)</code> it returns "UTF-8", "UTF-8", "UTF-8" but when I check <code>Encoding(x2$x)</code> it returns "unknown", "unknown", "unknown". </p>
  
  <p>trying to change the encoding with <code>Encoding(x2$x)&lt;- "UTF-8"</code> does not change the outcome. </p>
  
  <p>I have been working on this project for 3 months now with no issues. I can't understand why it would come on so suddenly. To my recollection, I have not changed any preferences or setting is R, Rstudion or my computer before this happened. The deadline for this project is coming up in a week and I am getting desperate for answers. If anyone could please help I would greatly appreciate it. Thank you</p>