I began by doing the obvious, I went to Install Packages and entered DiagrammeR. In the course of attempting to install, it complained of a wrong version of rtools. So I tried to install that. Later it complained of a wrong version of rlang.
There seem to be too many errors which are not specific to DiagrammeR.
How can I collect the necessary information to assist someone here in guiding me? Is there a way to get a listing of the installed packages and their versions?
Also, RStudio shows DiagrammeR among the installed packages. Can someone offer a simple example inserting a graph into an Rmd file? My attempts have been processed as plain text, not graphed.
UPDATE: System issues were responsible for some problems here. I have created a new installation in a VM and will pursue the issue with DiagrammeR (and other graphs) in a new topic.