lib unspecified & Error in loadNamespace
When you install the package using the RStudio package installer or directly from CRAN, it doesn't install the dependencies ("fracdiff", "Rcpp", "RcppArmadillo" and "colorspace") and hence, R keeps throwing the load namespace error. Installing the package through, automatically installs all the dependencies and solves this problem.
install.packages("forecast", repos = c("http://rstudio.org/_packages", "http://cran.rstudio.com"))
The last time I encountered a very similar problem, I used this code which I got somewhere:install.packages("package's name", repos=c("http://rstudio.org/_packages", "http://cran.rstudio.com")) simply put your package's name in the quotation marks.Hope this helps.