After installing R 4.0.0, I got a message that Rtools was out of date. I installed the new version of Rtools and now get the message:
WARNING: Rtools is required to build R packages but is not currently installed.
I tried setting the path as suggested as a previous fix (Sys.setenv(PATH = paste(Sys.getenv("PATH"), "C:\RTools40", "C:\RTools40\mingw64\bin", sep = ";")), etc.). This did not work.
Can anyone help with this?