title: how to uninstall (or fix) R-devel?
body: <p>I install the R-devel about a year ago and today I wanted to update to the current version. I installed and updated using instructions from here: <a href="http://singmann.org/installing-r-devel-on-linux/" rel="nofollow noreferrer">http://singmann.org/installing-r-devel-on-linux/</a></p>
  
  <p>However, I am getting the following error messages. Any help please? </p>
  
  <pre><code>Error: package or namespace load failed for ‘methods’:
  package ‘methods’ was installed by an R version with different internals; it needs to be reinstalled for use with this R version
  
  R Under development (unstable) (2018-04-17 r74612) -- "Unsuffered Consequences"
  Copyright (C) 2018 The R Foundation for Statistical Computing
  Platform: x86_64-pc-linux-gnu (64-bit)
  </code></pre>