Thank you for your response. The interesting is the error is not consistent. I tried different packages. From C:\Users\Tamás\Documents\R\win-library\4.0: magrittr and withr could be loaded, but ellipsis, crayon, tibble could not be loaded. From my C:\Program Files\R\R-4.0.0\library all packages could be loaded: class, lattice, splines, MASS.
How can set R or RStudio to install into the system level package library?