The version of this file is not compatible with the version of windows you're running.

[mara]

See the thread here:

Unable to select 32-bit R version in RStudio v1.2.1047-1 Preview

I am just unable to select 32 bit R version. I use RStudio v1.2.1047-1 Preview on Windows and R 3.5.1. Rstudio just silently sets 64 bit R, with no error messages.

TL;DR 32-bit is not currently supported in RStudio v1.2 (see thread for more details)