Warning message: 'c:/Rtools/mingw_/bin/g++' not found

Question

When I try to use RStan (which needs RTools to run) in R, I get the following warning message:

Warning message: In system(paste(CXX, ARGS), ignore.stdout = TRUE, ignore.stderr = TRUE): 'c:/Rtools/mingw_/bin/g++' not found

But, when I check in the 'c:/Rtools/' folder, I find two 'mingw_' files, called 'mingw_32' and 'min_gw64', and in both folders there is already a 'bin/g++' file. Why do I get this warning then? Is it wrong to have two folders, one 32 and one 64 bits?

Answer 1

delete your old.Rprofile and try again. This helped in my case