rs.BrowseForFolder() does not automatically return the focus to the Rhino window once the folder has been chosen. If one has a method that asks for typing something at the command line - like rs.GetString() - immediately after choosing the folder, typing directly doesn’t work, as the focus is no longer in Rhino. One has to click back in the Rhino window in order to be able to type at the command line.
Test script:
import rhinoscriptsyntax as rs
folder=rs.BrowseForFolder(message="Choose a folder")
name=rs.GetString("Type a name")
Run the script, choose a folder, then try to type the name.