[r] Error in file(file, "rt") : cannot open the connection

Set your working directory one level/folder higher. For example, if it is already set as:

setwd("C:/Users/Z/Desktop/Files/RStudio/Coursera/specdata")

go up one level back and set it as:

setwd("C:/Users/Z/Desktop/Files/RStudio/Coursera")

In other words, do not make "specdata" folder as your working directory.