I tried to install webkit2 greeters themes from the AUR, trying out wisp, ather, and even the deepin greeter (which I know isn’t the same webkit2, as I changed a line to make it lightdm-deepin-greeter).

First I did the deepin greeter, was OK, but I didn’t like the giant logo in the bottom left. Changed the line in lightdm.conf back = to lightdm-webkit2-greeter rather than lightdm-deepin-greeter.

Then I installed wisp which was a webkit2 theme on the AUR:
https://aur.archlinux.org/packages/lightdm-webkit-theme-wisp/
[0_1493714461958_lightdm-logs.tar.xz](Uploading 100%)
I then changed a line in lightdm-webkit2-greeter.conf to change theme antergos to wisp. I rebooted and the theme had an issue with the theme so it went into fallback mode and just went to the regular antergos themed greeter.

Then I installed aether another theme on the AUR:
https://aur.archlinux.org/packages/lightdm-webkit-theme-aether/

Again I changed the theme line to aether. However when I rebooted this time, lightdm failed to start. So then I uninstalled all the themes via yaourt -Rns and changed the theme line back to antergos. However lightdm still fails to start on boot. I am unsure of what these could have possibly changed, and I did not make edits other than what I’ve stated, and I’m sure I’ve typed back exactly what was there in the first place.

Right now I’m running gdm as a backup, but any help with fixing my lightdm would be appreciated.

lightdm.log contents:

[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.22.0, UID=0 PID=576
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG:   [LightDM] contains unknown option session-wrapper
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Monitoring logind for seats
[+0.00s] DEBUG: New seat added from logind: seat0
[+0.00s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.00s] DEBUG: Seat seat0: Starting
[+0.00s] DEBUG: Seat seat0: Creating greeter session
[+0.00s] DEBUG: Seat seat0: Failed to find session configuration lightdm-gtk-greeter ##greeter #lightdm-deepin-greeter
[+0.00s] DEBUG: Seat seat0: Failed to create greeter session
[+0.00s] DEBUG: Failed to start seat: seat0
libva info: VA-API version 0.40.0
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_40
libva info: va_openDriver() returns 0
file:///usr/share/lightdm-webkit/themes/wisp/js/main.js:145:11: CONSOLE ERROR ReferenceError: Can't find variable: lightdm

** (lightdm-webkit2-greeter:618): WARNING **: [ERROR] :: A problem was detected with the current theme. Falling back to default theme...

** (lightdm-webkit2-greeter:618): WARNING **: [ERROR] :: A problem was detected with the current theme. Falling back to default theme...

(lightdm-webkit2-greeter:618): Gtk-CRITICAL **: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed
[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.22.0, UID=0 PID=576
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG:   [LightDM] contains unknown option session-wrapper
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Registered seat module unity
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Monitoring logind for seats
[+0.00s] DEBUG: New seat added from logind: seat0
[+0.00s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.00s] DEBUG: Seat seat0: Starting
[+0.00s] DEBUG: Seat seat0: Creating greeter session
[+0.00s] DEBUG: Seat seat0: Failed to find session configuration lightdm-gtk-greeter ##greeter #lightdm-deepin-greeter
[+0.00s] DEBUG: Seat seat0: Failed to create greeter session
[+0.00s] DEBUG: Failed to start seat: seat0

seat0-greeter.log contents

libva info: VA-API version 0.40.0
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_40
libva info: va_openDriver() returns 0
file:///usr/share/lightdm-webkit/themes/wisp/js/main.js:145:11: CONSOLE ERROR ReferenceError: Can't find variable: lightdm

** (lightdm-webkit2-greeter:618): WARNING **: [ERROR] :: A problem was detected with the current theme. Falling back to default theme...

** (lightdm-webkit2-greeter:618): WARNING **: [ERROR] :: A problem was detected with the current theme. Falling back to default theme...

(lightdm-webkit2-greeter:618): Gtk-CRITICAL **: gtk_widget_destroy: assertion 'GTK_IS_WIDGET (widget)' failed

SOLVED!*******************

Do not be afraid to remake the lightdm.conf file by yourself! I re-wrote my lightdm.conf with the following lines

[LightDM]
log-directory=/var/log/lightdm
run-directory=/run/lightdm
 
[Seat:*]
session-wrapper=/etc/lightdm/Xsession
greeter-session=lightdm-webkit2-greeter
user-session=gnome                         

And though the other lightdm.conf file had only these un-commented, and it looks the same to me, the one I wrote booted.