Oct 11 14:19:16 columbia systemd[1]: Starting Light Display Manager...
Oct 11 14:19:16 columbia systemd[1]: Started Light Display Manager.
Oct 11 14:19:16 columbia systemd[1]: Started Process Core Dump (PID 781/UID 0). 
Oct 11 14:19:17 columbia systemd[1]: lightdm.service: Main process exited, code=exited, status=1/FAILURE
Oct 11 14:19:17 columbia systemd[1]: lightdm.service: Failed with result 'exit-code'.
Oct 11 14:19:17 columbia systemd-coredump[782]: Process 780 (Xorg) of user 0 dumped core.

                                                Stack trace of thread 780:
                                                #0  0x00007f9c795c1a85 __strlen_avx2 (libc.so.6 + 0x162a85)
                                                #1  0x00007f9c78b87706 get_cie_encoding (libgcc_s.so.1 + 0x11706)
                                                #2  0x00007f9c78b88663 get_fde_encoding (libgcc_s.so.1 + 0x12663)
                                                #3  0x00007f9c79598f95 dl_iterate_phdr (libc.so.6 + 0x139f95)
                                                #4  0x00007f9c78b892c6 _Unwind_Find_FDE (libgcc_s.so.1 + 0x132c6)
                                                #5  0x00007f9c78b85319 uw_frame_state_for (libgcc_s.so.1 + 0xf319)
                                                #6  0x00007f9c78b8733b _Unwind_Backtrace (libgcc_s.so.1 + 0x1133b)
                                                #7  0x00007f9c7956c116 __backtrace (libc.so.6 + 0x10d116)
                                                #8  0x000055d9acbaebd3 xorg_backtrace (Xorg + 0x146bd3)
                                                #9  0x000055d9acbb9a15 n/a (Xorg + 0x151a15)
Oct 11 14:19:17 columbia systemd[1]: systemd-coredump@5-781-0.service: Succeeded.
Oct 11 14:19:17 columbia systemd[1]: lightdm.service: Scheduled restart job, restart counter is at 1.
Oct 11 14:19:17 columbia systemd[1]: Stopped Light Display Manager.