After installing Xfce4 and SLiM login manager I have noticed that by just entering the user name and password would not sufficient to login to desktop because I get error message "SLiM failed to execute login command" all the time.
What could be the cause? Well, in your /etc/slim.conf you might have the login_cmd defined as:
login_cmd exec /bin/bash -login /usr/share/slim/Xsession %session
The only problem is that %session is not defined (by default). Remember when I've said that by selecting manually the X11 session I could login without error? What's happening is that by doing that I just define what would be the %session. If I choose Xfce4 then %session=Xfce4. If I choose "lxde" then %session=lxde. If I choose something else then %session="something else". You've got the idea.
You can get rid of this problem by adding the following line to your /etc/env.d/90xsession file as bellow:
After that everything should works as is supposed to.
Now, if you think that this article was interesting don't forget to rate it. It shows me that you care and thus I will continue write about these things.