I am using RStudio as frontend to R. It works perfectly on GNU/Linux (even with russian locale and russian messages). Hoewever, on Windows it works worse. The problem is with fonts or charsets of messages.
I installed RStudio Version 0.99.467 (AMD64) and R version 3.2.1 (2015-06-18).
I see the following prompt at the beginning (no issues with that, locale is en_US, english language):
R version 3.2.1 (2015-06-18) -- "World-Famous Astronaut"
Copyright (C) 2015 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64 (64-bit)
R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.
R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.
Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.
But when I try to do wrong thing, suppose trying to load package which is not installed, I see unreadable error message.
> library(abcdef)
Error in library(abcdef) : íåò ïàêåòà ïîä íàçâàíèåì ‘abcdef’
How to make it readable?
By the way, this problem appears only in RStudio. RGui works fine (even with russian messages, no suspicious letters):
> library(abcdef)
Ошибка в library(abcdef) :нет пакета под названием ‘abcdef’
(package "abcdef" is not installed).
Not sure where to start digging. Is it even resolvable? Or is it a bug in RStudio?
I think the problem is that you don't have non-Unicode russian charset (1251) on your system.
Ensure that locale is set to Russian in Control panel > Regional > Administrative > Change system locale, then restart your system and check if problem persists.
OR you can switch R language to English by adding language = EN to RConsole file in R's \etc\ directory (C:\Program Files\R\R-x.x.x\etc\ by default).