Failed to start Light Display Manager



Today I installed Arch on my desktop. So I decided to try several DE's. Firstly I installed gnome-desktop and gdm via

pacman -Syu gnome-desktop
pacman -Syu gdm
systemctl enable gdm.service

and everything worked fine.
Then I removed gnome-desktop via

pacman -Rscn gnome-desktop
systemctl disable gdm.service

and decided to install Deepin, I used

pacman -Syu deepin networkmanager lightdm
systemctl enable NetworkManager.service
systemctl enable lightdm.service

then I modified /etc/lightdm/lightdm.conf file following Wiki page and after reboot I saw this

I tried to google answer but it doesn't help me.
So what should I read or learn to solve this problem? Thanks in advance and sorry for my bad english

P.S. If you need something else, maybe some logs, ask me, I will give it.