Problem Accents Marks and other symbols in RStudio

I have a problem with RStudio. It doesn't allow me to put accent marks and other symbols like ^.
The issue is new, I've been working with RStudio fine for years. How could I fix it?

Hmm—could you let us know what version you're using, and your system specs?

I just typed in the code, below, which worked fine option + i in the case of ˆ.

c("â", "ê", "î", "ô", "û", "ŵ", "ŷ", "î")
#> [1] "â" "ê" "î" "ô" "û" "ŵ" "ŷ" "î"

Created on 2018-09-24 by the reprex package (v0.2.1.9000)