Can't unload a number of packages

Hi,

Am relatively new to R and have been working fine with it until yesterday when it won't unload some of my installed packages (tidyverse, ggthemes). I have tried uninstalling the packages and reinstalling them, uninstalling R but nothing seems to work. The packages appear to have downloaded fine, but just won't unpack. The code I am getting is ICU init failed: U_FILE_ACCESS_ERROR. r 2