Grub theme does not work

I installed Xenlism-Manjaro - Grub2 Theme on www.gnome-look.org.
When I run sudo bash install.sh in the folder it says:

  
        *************************
        *  Xenlism-Manjaro - Grub2 Theme  *
        ************************* 
  
Checking for root access...
 
  
Checking for the existence of themes directory...
 
  
Installing Xenlism-Manjaro theme...
 
  
Setting Xenlism-Manjaro as default...
 
Updating grub config...
Initializing grub config files ...
Found theme:/usr/share/grub/themes/Xenlism-Manjaro/theme.txt
Found Linux image:/boot/vmlinuz-linux-surface
Found initrd image:/boot/intel-ucode.img /boot/initramfs-linux-surface.img
Found initrd fallback image: /boot/initramfs-linux-surface-fallback.img
Found Linux image:/boot/vmlinuz-5.8-x86_64
Found initrd image:/boot/intel-ucode.img /boot/initramfs-5.8-x86_64.img
Found initrd fallback image: /boot/initramfs-5.8-x86_64-fallback.img
Found Windows Boot Manager at /dev/nvme0n1p1@/EFI/Microsoft/Boot/bootmgfw.efi
Adding boot menu entry for UEFI Firmware Settings ...
Found memtest86+ image: /boot/memtest86+/memtest.bin
/usr/bin/grub-probe:Warning: Unknown device nvme0n1.
Done
  
                  ***************
                  *  All done!  *
                  ***************

But when I reboot it says error and goes into the black and white grub theme.

kate boot/grub/grub.cfg
if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=zh_CN
  insmod gettext
fi
terminal_input console
terminal_output gfxterm
insmod part_gpt
insmod ext2
search --no-floppy --fs-uuid --set=root a0171029-3c83-48c8-ab35-3766d5c6f7a3
insmod gfxmenu
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/dejavu_32.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/dejavu_sans_12.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/dejavu_sans_14.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/dejavu_sans_16.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/dejavu_sans_24.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/dejavu_sans_48.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/terminus-12.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/terminus-14.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/terminus-16.pf2
loadfont ($root)/usr/share/grub/themes/Xenlism-Manjaro/terminus-18.pf2
insmod jpeg
insmod png
set theme=($root)/usr/share/grub/themes/Xenlism-Manjaro/theme.txt
export theme
kate /etc/default/grub
GRUB_THEME="/usr/share/grub/themes/Xenlism-Manjaro/theme.txt"
sudo update-grub

Just to be sure?

Nothing changed. Maybe I am using KDE so I lacked some software?

Sounds like you should report to the theme dev if their theme doesnt work :woman_shrugging: