@noemireyes could you try to run this workflow and see what the results are.
Have you checked what the settings are in the KNIME preferences. Are there any error messages?
Then the passages in the Log about WindowsDefenderExceptionHandler sound ominous. Could it be that you experience problems with a virus scanner?
And is your R and KNIME on a local installation/machine or maybe on some remote or virtual drive.
Then you could check if you could start and stop RServe outside KNIME from RStudio for example. This would be used with the R community nodes, but just to make sure.