R CRAN, install library Rcpp fails after R3.2 upgrade

Question

I upgraded from R-3.1 to R-3.2. OK ( Standard upgrade)

But this upgrade seems to have lost all the installed packages ( ggplot2, quantmod, Rcpp among dozens and doze

Answer 1

Packages are installed per version in R by default. Changes in the third part of the version number (e.g. 3.1.2 to 3.1.3) don't matter. But changes in the first and second parts (e.g. 3.1.3 to 3.2) do. If you want to move all your packages over, you can rename your library folder from (e.g) 3.1 to 3.2 while R isn't running. Then launch a vanilla R session and run update.packages(). If you're using Bioconductor packages, you'll want to use BiocInstaller::biocLite() instead to upgrade while keeping the current version of Bioconductor or BiocInstaller::biocLite("BiocUpgrade") to upgrade to the newest release. biocLite will by default prompt you to update CRAN packages too.

Note your library folder is by default something like %userprofile%\Documents\R\win-library\3.1.