I started with a Microsoft R Open 3.4.4 installation on my windows 10 desktop. I then installed R version 3.6.1 side-by-side. They each use only their own site library (no cross-over through a common user level package folder, just the one under the installation folder) with their own packages. However, when I run the 3.4.4 RGui I get the above error. I have even uninstalled the 3.6.1 version and still get the error.
Is there some sort of default workspace file on my machine that is loaded at start-up that has been updated that I can save down using the 3.4.4 version to prevent me getting this error, or is there some other way of enforcing complete isolation of R environments as I have a genuine requirement to have 3.4.4 and cannot just upgrade to a later version?