Hi, I have some more debugging info hoping that it helps understanding the problem:
>From :0-greeter.log. I tried to understand the code in loginManager.js:152. It seems that XDG_SESSION_ID mysteriously cannot be read. However, I am not sure if this is the problem. Apparently, also on "screenShield.js:766" some "Lock was blocked by an application" is being thrown. I have no idea, which application is causing this. Anyway, my problem is the same of this bugreport. gdm-greeter does not appear. Regards, Yusuf gnome-session[5683]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerChanged gnome-session[5683]: DEBUG(+): GsmDBusClient: obj_path=/org/gnome/SessionManager/Presence interface=org.freedesktop.DBus.Properties method=GetAll gnome-session[5683]: DEBUG(+): Detected that screensaver has appeared on the bus gnome-session[5683]: DEBUG(+): GsmDBusClient: obj_path=/org/freedesktop/DBus interface=org.freedesktop.DBus method=NameOwnerChanged JS ERROR: !!! Exception in callback for signal: sessions-loaded JS ERROR: !!! message = '"Argument 'string' (type utf8) may not be null"' JS ERROR: !!! fileName = '"/usr/share/gjs-1.0/overrides/GLib.js"' JS ERROR: !!! lineNumber = '105' JS ERROR: !!! stack = '"_pack_variant([object Array],null)@/usr/share/gjs-1.0/overrides/GLib.js:105 _pack_variant([object Array],[object Array])@/usr/share/gjs-1.0/overrides/GLib.js:152 ("(s)",[object Array])@/usr/share/gjs-1.0/overrides/GLib.js:262 _proxyInvoker("GetSession",false,[object Array],[object Array])@/usr/share/gjs-1.0/overrides/Gio.js:79 (null,function () {[native code]})@/usr/share/gjs-1.0/overrides/Gio.js:125 (function () {[native code]})@/usr/share/gnome-shell/js/misc/loginManager.js:152 wrapper(function () {[native code]})@/usr/share/gjs-1.0/lang.js:213 ()@/usr/share/gnome-shell/js/ui/screenShield.js:517 wrapper()@/usr/share/gjs-1.0/lang.js:213 ()@/usr/share/gjs-1.0/lang.js:154 ()@/usr/share/gjs-1.0/lang.js:248 _initializeUI()@/usr/share/gnome-shell/js/ui/main.js:163 _sessionsLoaded([object Object])@/usr/share/gnome-shell/js/ui/main.js:109 _emit("sessions-loaded")@/usr/share/gjs-1.0/signals.js:124 ([object Object])@/usr/share/gnome-shell/js/ui/sessionMode.js:172 done()@/usr/share/gnome-shell/js/misc/fileUtils.js:33 ([object Array])@/usr/share/gnome-shell/js/misc/fileUtils.js:51 onNextFileComplete([object GObject_Object],[object GObject_Object])@/usr/share/gnome-shell/js/misc/fileUtils.js:21 "' gnome-session[5683]: DEBUG(+): GsmDBusClient: obj_path=/org/gnome/SessionManager/Presence interface=org.freedesktop.DBus.Properties method=GetAll (gnome-shell:5935): GLib-GIO-WARNING **: Type of return value is incorrect: expected `(b)', got `()'' gnome-session[5683]: DEBUG(+): GsmPresence: setting idle: 1 JS LOG: pushModal: invocation of begin_modal failed JS LOG: pushModal: invocation of begin_modal failed JS LOG: error: Unable to lock: Lock was blocked by an application JS ERROR: !!! Exception in callback for signal: StatusChanged JS ERROR: !!! message = '"messageTray is null"' JS ERROR: !!! fileName = '"/usr/share/gnome-shell/js/ui/main.js"' JS ERROR: !!! lineNumber = '474' JS ERROR: !!! stack = '"notify("Unable to lock","Lock was blocked by an application")@/usr/share/gnome-shell/js/ui/main.js:474 notifyError("Unable to lock","Lock was blocked by an application")@/usr/share/gnome-shell/js/ui/main.js:494 (3)@/usr/share/gnome-shell/js/ui/screenShield.js:766 wrapper(3)@/usr/share/gjs-1.0/lang.js:213 ([object GObject_Object],":1.3",[object Array])@/usr/share/gnome-shell/js/ui/screenShield.js:504 _emit("StatusChanged",":1.3",[object Array])@/usr/share/gjs-1.0/signals.js:124 _convertToNativeSignal([object GObject_Object],":1.3","StatusChanged",[object GObject_Boxed])@/usr/share/gjs-1.0/overrides/Gio.js:130 "' gnome-session[5683]: DEBUG(+): Updating ConsoleKit idle status: 1 (gnome-settings-daemon:5703): color-plugin-WARNING **: failed to set screen _ICC_PROFILE: Failed to open file '/home/enygma/.local/share/icc/edid-56f7f3d18445b8bdcd3701a66b499991.icc': Permission denied gnome-session[5683]: Gdk-WARNING: gnome-session: Fatal IO error 11 (Resource temporarily unavailable) on X server :0. (gnome-settings-daemon:5703): Gdk-WARNING **: gnome-settings-daemon: Fatal IO error 11 (Resource temporarily unavailable) on X server :0. Window manager warning: Log level 16: gnome-shell: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.