I used to use R and Rstudio on my laptop at home (Dell, XPS 15 9550, Windows 10). Up to now (R 4.0.2, not sure of the previous version of Rstudio) I have had no problems.
Today, after updating to R 4.2.0 and Rstudio 2022.02.3 Build 492, the problem occurred.
From RGui I can connect to CRAN and install the packages. The installed packages are also available from Rstudio. However, when I try to Install from Package pain on Rstudio, I get
Warning: unable to access index for repository https://cran.rstudio.com/src/contrib:
cannot open URL 'https://cran.rstudio.com/src/contrib/PACKAGES'
and cannot install.
I have tried several times to change the mirror site and re-install R and Rstudio, but cannot solve the problem.
I'm not sure why I can install from RGui but not from RStudio.
I also tried temporarily turning off the firewall (Kaspersky Internet Security), but that did not solve the problem.
Thank you for your kind advise.