I had this problem: Unable to log into Ubuntu
So I reinstalled gnome, unity, lighdm and gdm. Unfortunately I don't understand much in this field (Xorg, I mean).
Now I have login screen, probably of gdm and I have much options in drop down list in bottom left corner, such as: "User defined session", "Ubuntu", "Gnome" and so on.
When I try "User defined session", window manager hangs on the login screen, but other options are working. So my questions are:
- How I can determine which window manager I use?
- What it mean "User define session" and where are its configuration files?
- Which logs I can monitor for find what the problem with login to "User defined session"?