Struggling to install older version of R - automatically updates to a newer version which I don't want

[Aimee]

Hello,

I am wanting to install a specific version of R (on my Mac) due to its compatibility with a package I need to analyse some data - the version is 3.4.2 and I downloaded it from https://cran.r-project.org/bin/macosx/el-capitan/base/

However, despite there being no issues with the install, when I open RStudio, the version used is a newer version - R version 3.4.3 and it doesn't seem to work at all with the package I want to use. I have never downloaded or installed this particular version (it is available at the same website provided above) so cannot figure out where it is coming from - this occurs in both R console and RStudio. However, interestingly, if I just open the R.app in my applications and then open the 'About R' menu, it shows the 'correct' version.

For specifics,
RStudio version: 1.1.463 (I also tried a newer version with no success)
R version downloaded: 3.4.2
R version that opens (never downloaded): 3.4.3
Mac OS: version 10.14.6 (Mojave)

Thanks in advance,
Aimee

[technocrat]

See the support post on multiple R versions. Expect accumulating issues generally as installed versions of macOS, R and RStudio age. It's not necessary to be at the latest release of everything, but it is best to keep at the current major release on all three— 10.15.x for macOS, 4.02 for R, due to a bug in the initial release that affects macOS, and RStudio 1.3.x.