Does the lightdm.log say anything useful? The stack trace looks like an out of memory condition, which could be either liblightdm or GTK+ failing to work? I'd suggest trying different versions of those libraries.
Does the lightdm.log say anything useful? The stack trace looks like an out of memory condition, which could be either liblightdm or GTK+ failing to work? I'd suggest trying different versions of those libraries.