Thanks for replying!!
so it must be something in your dotfiles then
Sorry, but I am not skilled yet in the Linux jargon, so what are 'dotfiles'? do you mean to the hidden files which their name begin with a dot? if yes, so I've noticed that when I'm trying to access the .Xauthority file with the ls command for example, it emits an 'input output error' message. unfortunately I'm don't know how to fix that. I will be happy to get some hints.
Regards, atar.