Fatal error in R

[Violet-issak]

HI

I am having a problem in installing a package named AOI using this code: remotes::install_github("mikejohnson51/AOI"), it was giving a problem with package named prettyunits, it is like it can't be installed without this package and the same package was interupting it from being installed, and then started another problem with the version of xfun package, I tried to install the new version but i couldn't, and I recived a message of fatal error in R, so I deleted the xfun package and now R does not work at all, it gives me this error message for any code I type such as a = 1+2
Error in loadNamespace(j <- i[[1L]], c(lib.loc, .libPaths()), versionCheck = vI[[j]]) :
there is no package called ‘xfun’

I hope some one can help me in this issue, I would uninstall R and reinstall it, but I want to know why I am having problem whenever I want to install any package from github?