I've encountered encoding problem, and being tried to solve it through several ways.
encoding="UTF-8" >>> didn't work
global options > Code > Saving > UTF-8 setting >>> didn't work
And I found that that the menu (File / Reopen with Encoding) was not activated on my RStudio, so I thought that there might be some problem in the installation.
But I can't activate the menu ('Reopen with Encoding) even though I've installed R and RStudio several times.
Would you give me some advice for this?