title: Cannot Change the Version of R in RStudio
body: <p>My RStudio (V 0.99.491) is inept to change the R Version.
  I act in the ordinary way through <code>Global Options --&gt; R-Version</code>. Afterwards it hangs and doesn't work or react any more. The initial version of R which works fine is <code>R 3.1.0</code>. I have never had such a problem before. Maybe someone has faced with a similar problem. </p>
  
  <p>I tried to uninstall RStudio, and install it again, but this hasn't help to fix the issue.</p>