Hi, and welcome!
Please see the FAQ: What's a reproducible example (`reprex`) and how do I create one? Using a reprex, complete with representative data will attract quicker and more answers. This question doesn't require one, because it's a self descriptive error message, but please keep this in mind for any coding questions.
The key line in the error message is
namespace ‘rlang’ 0.4.2 is already loaded, but >= 0.4.5 is required
It's telling us that the rlang package version is out-of-date.
The normal result of
install.packages("rlang")
is nothing when rlang is up-to-date.
Running
sessionInfo()
#> R version 3.6.2 (2019-12-12)
#> Platform: x86_64-apple-darwin15.6.0 (64-bit)
#> Running under: macOS Catalina 10.15.3
#>
#> Matrix products: default
#> BLAS: /Library/Frameworks/R.framework/Versions/3.6/Resources/lib/libRblas.0.dylib
#> LAPACK: /Library/Frameworks/R.framework/Versions/3.6/Resources/lib/libRlapack.dylib
#>
#> locale:
#> [1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
#>
#> attached base packages:
#> [1] stats graphics grDevices utils datasets methods base
#>
#> loaded via a namespace (and not attached):
#> [1] compiler_3.6.2 magrittr_1.5 tools_3.6.2 htmltools_0.4.0
#> [5] yaml_2.2.1 Rcpp_1.0.4 stringi_1.4.6 rmarkdown_2.1
#> [9] highr_0.8 knitr_1.28 stringr_1.4.0 xfun_0.12
#> [13] digest_0.6.25 rlang_0.4.5 evaluate_0.14
Created on 2020-03-18 by the reprex package (v0.3.0)
shows the current versions of packages in the installation.
What I'd suggest is
install.packages("rlang")
from the console pane, quitting, restarting, then
library(rlang)
sessionInfo()
Under loaded via a namespace (and not attached):
you should now see rlang_0.4.5