[Galaxy S 4 i9505 Original Android Development] theleftykid:
I need help please with the error.. I use the first method on this guide https://xdaforums.com/android/development/guide-dualboot-patcher-unsupported-t3647056 to Add support on my device LG v20 h990ds. Patching the Lineage OS 15 was successful but when I try to flash the patched ROM I get this error...

[MultiBoot] Installing to dual

[MultiBoot] ROM ID: dual

[MultiBoot] - /system: /system/multiboot/dual/system

[MultiBoot] - /cache: /cache/multiboot/dual/cache

[MultiBoot] - /data: /data/multiboot/dual/data

[MultiBoot] - System is image file: false

[MultiBoot] - Cache is image file: false

[MultiBoot] - Data is image file: false

[2019-01-03T17:25:02.032132000-06:00][612:612][V] m/r/installer: ROM ID: dual

[2019-01-03T17:25:02.032151000-06:00][612:612][D] m/r/installer: [Installer] Chroot set up stage

[2019-01-03T17:25:02.235308000-06:00][612:612][V] m/r/installer: Won't switch to non-existent target ROM

[2019-01-03T17:25:02.235386000-06:00][612:612][V] m/r/installer: Patching ramdisk to undo init modifications

[2019-01-03T17:25:02.235499000-06:00][612:612][D] m/r/installer_util: Patching boot image

[2019-01-03T17:25:02.235514000-06:00][612:612][D] m/r/installer_util: - Input: /dev/block/platform/soc/624000.ufshc/by-name/boot

[2019-01-03T17:25:02.235536000-06:00][612:612][D] m/r/installer_util: - Output: /multiboot/boot.img

[2019-01-03T17:25:02.236311000-06:00][612:612][D] m/r/installer_util: - Format: android

[2019-01-03T17:25:02.236346000-06:00][612:612][D] m/r/installer_util: /multiboot/boot.img: Writer is requesting entry type: 1

[2019-01-03T17:25:02.236374000-06:00][612:612][D] m/r/installer_util: /multiboot/boot.img: Writing patched kernel

[2019-01-03T17:25:02.389609000-06:00][612:612][D] m/r/installer_util: /multiboot/boot.img: Writer is requesting entry type: 2

[2019-01-03T17:25:02.389711000-06:00][612:612][D] m/r/installer_util: /multiboot/boot.img: Writing patched ramdisk

[2019-01-03T17:25:02.537617000-06:00][612:612][D] m/r/ramdisk_patcher: [init] Target init path: /multiboot/boot.img.8pdpRa/ramdisk.out.c6E2Mt/init

[2019-01-03T17:25:04.179386000-06:00][612:612][D] m/r/installer_util: /multiboot/boot.img: Writer is requesting entry type: 4

[2019-01-03T17:25:04.179507000-06:00][612:612][V] m/r/installer_util: /dev/block/platform/soc/624000.ufshc/by-name/boot: Skipping non-existent boot image entry: 4

[2019-01-03T17:25:04.179539000-06:00][612:612][D] m/r/installer_util: /multiboot/boot.img: Writer is requesting entry type: 8

[2019-01-03T17:25:04.179568000-06:00][612:612][V] m/r/installer_util: /dev/block/platform/soc/624000.ufshc/by-name/boot: Skipping non-existent boot image entry: 8

[2019-01-03T17:25:04.888634000-06:00][612:612][D] m/r/installer: [Installer] Filesystem mounting stage

[2019-01-03T17:25:04.891750000-06:00][612:612][D] m/r/image: /data/.system.img.tmp: Creating new 5863636992 ext4 image

[2019-01-03T17:25:04.891836000-06:00][612:612][D] m/command: Running executable: make_ext4fs

[2019-01-03T17:25:05.130558000-06:00][612:612][V] m/r/image: make_ext4fs: Creating filesystem with parameters:

[2019-01-03T17:25:05.130923000-06:00][612:612][V] m/r/image: make_ext4fs: Size: 5863636992

[2019-01-03T17:25:05.131044000-06:00][612:612][V] m/r/image: make_ext4fs: Block size: 4096

[2019-01-03T17:25:05.131196000-06:00][612:612][V] m/r/image: make_ext4fs: Blocks per group: 32768

[2019-01-03T17:25:05.131341000-06:00][612:612][V] m/r/image: make_ext4fs: Inodes per group: 8144

[2019-01-03T17:25:05.131488000-06:00][612:612][V] m/r/image: make_ext4fs: Inode size: 256

[2019-01-03T17:25:05.131585000-06:00][612:612][V] m/r/image: make_ext4fs: Journal blocks: 22368

[2019-01-03T17:25:05.131717000-06:00][612:612][V] m/r/image: make_ext4fs: Label:

[2019-01-03T17:25:05.131814000-06:00][612:612][V] m/r/image: make_ext4fs: Blocks: 1431552

[2019-01-03T17:25:05.131897000-06:00][612:612][V] m/r/image: make_ext4fs: Block groups: 44

[2019-01-03T17:25:05.131978000-06:00][612:612][V] m/r/image: make_ext4fs: Reserved block group size: 351

[2019-01-03T17:25:05.132111000-06:00][612:612][V] m/r/image: make_ext4fs: Created filesystem with 11/358336 inodes and 47679/1431552 blocks

[MultiBoot] Copying system to temporary image

[2019-01-03T17:25:05.140909000-06:00][612:612][E] m/r/installer: Failed to create /system/multiboot/dual/system: Read-only file system

[MultiBoot] Failed to copy /system/multiboot/dual/system to /data/.system.img.tmp

[2019-01-03T17:25:05.141456000-06:00][612:612][D] m/r/installer: [Installer] Cleanup stage

[MultiBoot] Failed to flash zip file.

[MultiBoot] Destroying chroot environment

[2019-01-03T17:25:00.174919000-06:00][612:612][E] m/r/installer: Failed to unmount /chroot/system: Invalid argument

[2019-01-03T17:25:00.174983000-06:00][612:612][E] m/r/installer: Failed to unmount /chroot/cache: Invalid argument

[2019-01-03T17:25:00.175011000-06:00][612:612][E] m/r/installer: Failed to unmount /chroot/data: Invalid argument

[2019-01-03T17:25:00.175037000-06:00][612:612][E] m/r/installer: Failed to unmount /chroot/efs: Invalid argument

[2019-01-03T17:25:00.176257000-06:00][612:612][E] m/r/installer: Failed to unmount /chroot/sbin: Invalid argument

[2019-01-03T17:25:00.176321000-06:00][612:612][E] m/r/installer: Failed to unmount /chroot: Device or resource busy

[2019-01-03T17:25:00.176848000-06:00][612:612][D] m/mount: Attempting to unmount /chroot/mb/bind.data

[2019-01-03T17:25:00.177215000-06:00][612:612][D] m/mount: Attempting to unmount /chroot/mb/bind.cache

[2019-01-03T17:25:00.177520000-06:00][612:612][D] m/mount: Attempting to unmount /chroot

[2019-01-03T17:25:00.184318000-06:00][612:612][E] m/r/installer: /efs: path not mounted

Please help what to do.. Thank you!