Could not find resource 'data/tools/gptmbr.bin'.

Followed these instructions: https://itsfoss.com/multiple-linux-one-usb/
Installed the debian package on Ubuntu 20.04 x86-64. ODROID-H2+ M.2 NVMe drive.
USB stick: SanDisk 128GB Extreme PRO USB 3.1 Solid State Flash Drive
ISO file to be added resides on WD SSD with btrfs.
When adding the gparted live iso file, I saw it reach 100% but then it crashed like so.
started with sudo "multibootusb"
sryan@odroid-h2:~$ sudo multibootusb
[sudo] password for sryan: 
/usr/bin/multibootusb:194: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  if uninstall is True and config.usb_disk is not '':
/usr/bin/multibootusb:196: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif uninstall is True and config.usb_disk is '':
/usr/bin/multibootusb:200: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif config.image_path is '' and config.usb_disk is '':
/usr/bin/multibootusb:200: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif config.image_path is '' and config.usb_disk is '':
/usr/bin/multibootusb:203: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  elif config.cli_syslinux is True and config.usb_disk is not '':
/usr/bin/multibootusb:205: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif config.image_path is '' or config.usb_disk is '':
/usr/bin/multibootusb:205: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif config.image_path is '' or config.usb_disk is '':
Using python version  3.8.2 (default, Jul 16 2020, 14:00:26) 
[GCC 9.3.0] on platform Linux-5.4.0-42-generic-x86_64-with-glibc2.29
Could not find resource 'data/tools/gdisk/gdisk.exe'.
Running multibootusb version 9.2.0 from installed system...
Starting multibootusb GUI...
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-root'
Cleaning old multibootusb directory...
Syslinux exist in multibootusb directory...
Using pyudev for detecting USB drives...
    /dev/sdb
    /dev/sdb1
Selected device /dev/sdb
Device /dev/sdb is a GPT disk...
USB disk is not mounted and can't update list widget...
Selected device /dev/sdb1
/media/root/FLASH
Device /dev/sdb1 is a GPT disk...
Executing ==> 7z -ssc-  x -y "/media/btrfs/images/gparted-live-1.1.0-5-amd64.iso" -o"/root/.multibootusb/iso_cfg_ext_dir" "*.cfg" -r 2> /dev/null
Executing ==> 7z -ssc-  x -y "/media/btrfs/images/gparted-live-1.1.0-5-amd64.iso" -o"/root/.multibootusb/iso_cfg_ext_dir" "*.txt" -r 2> /dev/null
Executing ==> 7z -ssc-  x -y "/media/btrfs/images/gparted-live-1.1.0-5-amd64.iso" -o"/root/.multibootusb/iso_cfg_ext_dir" "*isolinux.bin" -r 2> /dev/null
Executing ==> 7z -ssc-  x -y "/media/btrfs/images/gparted-live-1.1.0-5-amd64.iso" -o"/root/.multibootusb/iso_cfg_ext_dir" "*.lst" -r 2> /dev/null
Persistence option is available.
Persistence Max Size: 4.0G
MultiBoot Install: USB Disk: /dev/sdb1
MultiBoot Install: USB Label: FLASH
MultiBoot Install: USB UUID: CFE3-2DC9
MultiBoot Install: USB mount path: /media/root/FLASH
MultiBoot Install: Disk total size: 119.2G
MultiBoot Install: Disk used size: 32.0K
MultiBoot Install: Disk free size: 119.2G
MultiBoot Install: Filesystem: vfat
MultiBoot Install: Disk vendor: SanDisk
MultiBoot Install: Disk model: Extreme_Pro
MultiBoot Install: ISO file: gparted-live-1.1.0-5-amd64.iso
MultiBoot Install: Distro type detected: debian
Persistence chosen is 0B
Copying multibootusb directory to /media/root/FLASH
EFI/BOOT directory does not exist. Creating new.
Copying EFI directory to /media/root/FLASH
Installing gparted-live-1.1.0-5-amd64.iso on /media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64
Executing ==> 7z -ssc-  x -y -o"/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64" "/media/btrfs/images/gparted-live-1.1.0-5-amd64.iso" 2> /dev/null
ISO extracted successfully. Sync is in progress...############################|

Found syslinux version 6

Copying chain.c32
('/root/.multibootusb/syslinux/modules/6/chain.c32', '/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64/syslinux/chain.c32')
Copying ldlinux.c32
('/root/.multibootusb/syslinux/modules/6/ldlinux.c32', '/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64/syslinux/ldlinux.c32')
Copying libcom32.c32
('/root/.multibootusb/syslinux/modules/6/libcom32.c32', '/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64/syslinux/libcom32.c32')
Copying libutil.c32
('/root/.multibootusb/syslinux/modules/6/libutil.c32', '/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64/syslinux/libutil.c32')
Copying menu.c32
('/root/.multibootusb/syslinux/modules/6/menu.c32', '/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64/syslinux/menu.c32')
Copying vesamenu.c32
('/root/.multibootusb/syslinux/modules/6/vesamenu.c32', '/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64/syslinux/vesamenu.c32')
Distro extraction completed...

Found syslinux version 6

Executing ==> /root/.multibootusb/syslinux/bin/syslinux6 -i -d "/multibootusb/gparted-live-1.1.0-5-amd64/syslinux" /dev/sdb1

Syslinux install on distro directory is successful...

Executing ==> dd if=/dev/sdb1 of="/media/root/FLASH/multibootusb/gparted-live-1.1.0-5-amd64/syslinux/debian.bs" count=1

1+0 records in
1+0 records out
512 bytes copied, 0.104817 s, 4.9 kB/s

Bootsector copy is successful...

Using gptmbr.bin for mbr install.
Could not find resource 'data/tools/gptmbr.bin'.
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/scripts/mbusb_gui.py", line 349, in install_syslinux
    syslinux_default(config.usb_disk)
  File "/usr/lib/python3/dist-packages/scripts/syslinux.py", line 107, in syslinux_default
    mbr_install_cmd = 'dd bs=440 count=1 conv=notrunc if=' + mbr_bin + ' of=' + usb_disk[:-1]
TypeError: can only concatenate str (not "NoneType") to str
mbusb / multibootusb

Could not find resource 'data/tools/gptmbr.bin'. #525
