Hi, and welcome!
Please see the FAQ: What's a reproducible example (`reprex`) and how do I do 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rlang package version is out-of-date.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
is nothing when rlang is up-to-date.
#> 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
#>  en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8
#> attached base packages:
#>  stats graphics grDevices utils datasets methods base
#> loaded via a namespace (and not attached):
#>  compiler_3.6.2 magrittr_1.5 tools_3.6.2 htmltools_0.4.0
#>  yaml_2.2.1 Rcpp_1.0.4 stringi_1.4.6 rmarkdown_2.1
#>  highr_0.8 knitr_1.28 stringr_1.4.0 xfun_0.12
#>  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
from the console pane, quitting, restarting, then
loaded via a namespace (and not attached):
you should now see