[Kindle Fire HDX 7" & 8.9" General] niksssss:
Oh very sorry for the rookie mistake. I haven't used the HDX for a lot of time and I thought it was rooted. However I am rooted now (tested from adb) and I still get the same error, but I think the log is a bit different

Log:

[ 0.000000] Linux version 4.7.4-hardened-r1 (root@eleven) (gcc version 4.9.3 (Gentoo 4.9.3 p1.5, pie-0.6.4) ) #2 PREEMPT Sat Sep 24 20:36:02 CEST 2016

[ 0.000000] KERNEL supported cpus:

[ 0.000000] Intel GenuineIntel

[ 0.000000] x86/fpu: Legacy x87 FPU detected.

[ 0.000000] x86/fpu: Using 'eager' FPU context switches.

[ 0.000000] e820: BIOS-provided physical RAM map:

[ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable

[ 0.000000] BIOS-e820: [mem 0x000000000009fc00-0x000000000009ffff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved

[ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x0000000007feffff] usable

[ 0.000000] BIOS-e820: [mem 0x0000000007ff0000-0x0000000007ffffff] ACPI data

[ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec00fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved

[ 0.000000] BIOS-e820: [mem 0x00000000fffc0000-0x00000000ffffffff] reserved

[ 0.000000] Notice: NX (Execute Disable) protection missing in CPU!

[ 0.000000] e820: last_pfn = 0x7ff0 max_arch_pfn = 0x100000

[ 0.000000] ACPI: Early table checksum verification disabled

[ 0.000000] ACPI: RSDP 0x00000000000E0000 000024 (v02 VBOX )

[ 0.000000] ACPI: XSDT 0x0000000007FF0030 000034 (v01 VBOX VBOXXSDT 00000001 ASL 00000061)

[ 0.000000] ACPI: FACP 0x0000000007FF00F0 0000F4 (v04 VBOX VBOXFACP 00000001 ASL 00000061)

[ 0.000000] ACPI: DSDT 0x0000000007FF0410 00210F (v01 VBOX VBOXBIOS 00000002 INTL 20100528)

[ 0.000000] ACPI: FACS 0x0000000007FF0200 000040

[ 0.000000] ACPI: FACS 0x0000000007FF0200 000040

[ 0.000000] ACPI: SSDT 0x0000000007FF0240 0001CC (v01 VBOX VBOXCPUT 00000002 INTL 20100528)

[ 0.000000] 127MB LOWMEM available.

[ 0.000000] mapped low ram: 0 - 07ff0000

[ 0.000000] low ram: 0 - 07ff0000

[ 0.000000] Zone ranges:

[ 0.000000] Normal [mem 0x0000000000001000-0x0000000007feffff]

[ 0.000000] Movable zone start for each node

[ 0.000000] Early memory node ranges

[ 0.000000] node 0: [mem 0x0000000000001000-0x000000000009efff]

[ 0.000000] node 0: [mem 0x0000000000100000-0x0000000007feffff]

[ 0.000000] Initmem setup node 0 [mem 0x0000000000001000-0x0000000007feffff]

[ 0.000000] Using APIC driver default

[ 0.000000] Found and enabled local APIC!

[ 0.000000] e820: [mem 0x08000000-0xfebfffff] available for PCI devices

[ 0.000000] clocksource: refined-jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 6370452778343963 ns

[ 0.000000] Built 1 zonelists in Zone order, mobility grouping on. Total pages: 32398

[ 0.000000] Kernel command line: console=ttyS0 tsc=reliable

[ 0.000000] PID hash table entries: 512 (order: -1, 2048 bytes)

[ 0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes)

[ 0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes)

[ 0.000000] Initializing CPU#0

[ 0.000000] Memory: 105040K/130616K available (1827K kernel code, 159K rwdata, 292K rodata, 21836K init, 96K bss, 25576K reserved, 0K cma-reserved)

[ 0.000000] virtual kernel memory layout:

[ 0.000000] fixmap : 0xfffa2000 - 0xfffff000 ( 372 kB)

[ 0.000000] vmalloc : 0xc87f0000 - 0xfffa0000 ( 887 MB)

[ 0.000000] lowmem : 0xc0000000 - 0xc7ff0000 ( 127 MB)

[ 0.000000] .init : 0xc1248000 - 0xc279b000 (21836 kB)

[ 0.000000] .data : 0xc1217000 - 0xc123ec60 ( 159 kB)

[ 0.000000] .text : 0xc1000000 - 0xc11c9001 (1828 kB)

[ 0.000000] Checking if this processor honours the WP bit even in supervisor mode...Ok.

[ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1

[ 0.000000] Preemptible hierarchical RCU implementation.

[ 0.000000] Build-time adjustment of leaf fanout to 32.

[ 0.000000] NR_IRQS:2304 nr_irqs:32 16

[ 0.000000] console [ttyS0] enabled

[ 0.000000] tsc: Fast TSC calibration using PIT

[ 0.000000] tsc: Detected 2592.212 MHz processor

[ 0.000314] Calibrating delay loop (skipped), value calculated using timer frequency.. 5186.44 BogoMIPS (lpj=8640706)

[ 0.012090] pid_max: default: 32768 minimum: 501

[ 0.069893] ACPI: Core revision 20160422

[ 0.073955] ACPI: 2 ACPI AML tables successfully acquired and loaded

[ 0.081615]

[ 0.081790] ACPI: setting ELCR to 0200 (from 0e00)

[ 0.085501] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes)

[ 0.088394] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes)

[ 0.095523] process: using mwait in idle threads

[ 0.099558] Last level iTLB entries: 4KB 64, 2MB 8, 4MB 8

[ 0.102182] Last level dTLB entries: 4KB 64, 2MB 0, 4MB 0, 1GB 4

[ 0.103887] CPU: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz (family: 0x6, model: 0x5e, stepping: 0x3)

[ 0.120404] Performance Events: no PMU driver, software events only.

[ 0.167214] Enabling APIC mode: Flat. Using 0 I/O APICs

[ 0.381348] devtmpfs: initialized

[ 0.438465] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 6370867519511994 ns

[ 0.532997] NET: Registered protocol family 16

[ 0.548571] ACPI: bus type PCI registered

[ 0.572959] bios32_service: base:000f0000 length:0000f000 entry:0000da26

[ 0.587720] PCI: PCI BIOS revision 2.10 entry at 0xda26, last bus=0

[ 0.692950] PCI: Using configuration type 1 for base access

[ 0.799507] ACPI: Added _OSI(Module Device)

[ 0.860551] ACPI: Added _OSI(Processor Device)

[ 0.915379] ACPI: Added _OSI(3.0 _SCP Extensions)

[ 0.970356] ACPI: Added _OSI(Processor Aggregator Device)

[ 1.000950] ACPI: Executed 1 blocks of module-level executable AML code

[ 1.008826] ACPI: Interpreter enabled

[ 1.034496] ACPI: (supports S0 S5)

[ 1.048283] ACPI: Using PIC for interrupt routing

[ 1.050093] PCI: Using host bridge windows from ACPI; if necessary, use "pci=nocrs" and report a bug

[ 1.069086] ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-ff])

[ 1.133719] acpi PNP0A03:00: _OSC: OS supports [ASPM ClockPM Segments MSI]

[ 1.237700] acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM

[ 1.241572] acpi PNP0A03:00: fail to add MMCONFIG information, can't access extended PCI configuration space under this bridge.

[ 1.285339] PCI host bridge to bus 0000:00

[ 1.293223] pci_bus 0000:00: root bus resource [io 0x0000-0x0cf7 window]

[ 1.296045] pci_bus 0000:00: root bus resource [io 0x0d00-0xffff window]

[ 1.336750] pci_bus 0000:00: root bus resource [mem 0x000a0000-0x000bffff window]

[ 1.386452] pci_bus 0000:00: root bus resource [mem 0x08000000-0xffdfffff window]

[ 1.470956] pci_bus 0000:00: root bus resource [bus 00-ff]

[ 1.491730] pci 0000:00:01.1: legacy IDE quirk: reg 0x10: [io 0x01f0-0x01f7]

[ 1.507231] pci 0000:00:01.1: legacy IDE quirk: reg 0x14: [io 0x03f6]

[ 1.518395] pci 0000:00:01.1: legacy IDE quirk: reg 0x18: [io 0x0170-0x0177]

[ 1.523372] pci 0000:00:01.1: legacy IDE quirk: reg 0x1c: [io 0x0376]

[ 1.544803] ACPI: PCI Interrupt Link [LNKA] (IRQs 5 *9 10 11)

[ 1.576328] ACPI: PCI Interrupt Link [LNKB] (IRQs 5 9 10 *11)

[ 1.581317] ACPI: PCI Interrupt Link [LNKC] (IRQs 5 9 10 *11)

[ 1.612235] ACPI: PCI Interrupt Link [LNKD] (IRQs 5 9 *10 11)

[ 1.660971] ACPI: Enabled 2 GPEs in block 00 to 07

[ 1.682847] ACPI: bus type USB registered

[ 1.686906] usbcore: registered new interface driver usbfs

[ 1.691058] usbcore: registered new interface driver hub

[ 1.698140] usbcore: registered new device driver usb

[ 1.762047] PCI: Using ACPI for IRQ routing

[ 1.822369] clocksource: Switched to clocksource refined-jiffies

[ 1.832042] pnp: PnP ACPI init

[ 1.834271] pnp: PnP ACPI: found 3 devices

[ 1.836494] NET: Registered protocol family 2

[ 1.840911] TCP established hash table entries: 1024 (order: 0, 4096 bytes)

[ 1.858063] TCP bind hash table entries: 1024 (order: 0, 4096 bytes)

[ 1.861992] TCP: Hash tables configured (established 1024 bind 1024)

[ 1.864872] UDP hash table entries: 256 (order: 0, 4096 bytes)

[ 1.868779] UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)

[ 1.872757] NET: Registered protocol family 1

[ 2.402916] platform rtc_cmos: registered platform RTC device (no PNP device found)

[ 2.548960] futex hash table entries: 256 (order: -1, 3072 bytes)

[ 2.552130] workingset: timestamp_bits=29 max_order=15 bucket_order=0

[ 2.559056] Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)

[ 2.569274] io scheduler noop registered

[ 2.577091] io scheduler deadline registered

[ 2.626759] io scheduler cfq registered (default)

[ 2.660951] Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled

[ 2.713148] 00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A

[ 2.877235] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver

[ 2.907195] ehci-pci: EHCI PCI platform driver

[ 2.924615] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver

[ 3.027807] ohci-pci: OHCI PCI platform driver

[ 3.030373] ACPI: PCI Interrupt Link [LNKB] enabled at IRQ 11

[ 3.033455] ohci-pci 0000:00:06.0: OHCI PCI host controller

[ 3.060916] ohci-pci 0000:00:06.0: new USB bus registered, assigned bus number 1

[ 3.066160] ohci-pci 0000:00:06.0: irq 11, io mem 0xf0404000

[ 3.122322] usb usb1: New USB device found, idVendor=1d6b, idProduct=0001

[ 3.267650] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1

[ 3.312300] usb usb1: Product: OHCI PCI host controller

[ 3.314894] usb usb1: Manufacturer: Linux 4.7.4-hardened-r1 ohci_hcd

[ 3.377131] usb usb1: SerialNumber: 0000:00:06.0

[ 3.378940] hub 1-0:1.0: USB hub found

[ 3.381657] hub 1-0:1.0: 12 ports detected

[ 3.383552] uhci_hcd: USB Universal Host Controller Interface driver

[ 3.385492] usbcore: registered new interface driver usbserial

[ 3.404634] usbcore: registered new interface driver usbserial_generic

[ 3.483999] usbserial: USB Serial support registered for generic

[ 3.506864] usbcore: registered new interface driver usb_serial_simple

[ 3.675704] usbserial: USB Serial support registered for carelink

[ 3.748030] usbserial: USB Serial support registered for zio

[ 3.869777] usbserial: USB Serial support registered for funsoft

[ 3.937130] usbserial: USB Serial support registered for flashloader

[ 4.029055] usbserial: USB Serial support registered for google

[ 4.130947] usbserial: USB Serial support registered for vivopay

[ 4.197675] usbserial: USB Serial support registered for moto_modem

[ 4.277788] usbserial: USB Serial support registered for novatel_gps

[ 4.279511] usbserial: USB Serial support registered for hp4x

[ 4.283302] usbserial: USB Serial support registered for suunto

[ 4.286983] usbserial: USB Serial support registered for siemens_mpi

[ 4.291982] Using IPI Shortcut mode

[ 4.315251] Freeing unused kernel memory: 21836K (c1248000 - c279b000)

[ 4.407248] Write protecting the kernel text: 1832k

[ 4.412197] Write protecting the kernel read-only data: 308k

Welcome to 1-Click

mount: proc mounted on /pr[ 4.596308] random: adb: uninitialized urandom read (32 bytes read, 2 bits of entropy available)

oc.

mount: sys mounted on /sys.

mount: dev mounted on /dev.

* daemon not runn[ 4.900276] usb 1-1: new full-speed USB device number 2 using ohci-pci

ing. starting it now on port 5037 *

* daemon started successfully *

[ 5.635329] usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x81 has invalid maxpacket 512, setting to 64

[ 5.724903] usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x1 has invalid maxpacket 512, setting to 64

[ 5.809698] usb 1-1: config 1 interface 1 altsetting 0 endpoint 0x83 has invalid maxpacket 512, setting to 64

[ 5.816078] usb 1-1: config 1 interface 1 altsetting 0 endpoint 0x2 has invalid maxpacket 512, setting to 64

[ 5.851571] usb 1-1: New USB device found, idVendor=1949, idProduct=000c

[ 5.964952] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

[ 6.082448] usb 1-1: Product: Android

[ 6.172787] usb 1-1: Manufacturer: Android

[ 6.194838] usb 1-1: SerialNumber: D0FBA0A034940HN0

Hit [Enter] to continue

Please make sure ADB is enabled on your Kindle

and connect the device to your computer

In case you don't already know, ADB is enabled by turning on the

'Settings/Device[ Options]/Developer Options/Enable ADB' option.

If 'Developer Options' is missing in 'Settings/Device[ Options]',

tapping 'Settings/Device[ Options]/Serial Number' seven times

will enable it..

Hit [Enter] to continue

[ 12.647857] TCP: request_sock_TCP: Possible SYN flooding on port 5037. Sending cookies. Check SNMP counters.

1) D0FBA0A034940HN0 -- **UNSUPPORTED** (thor/Kindle_Fire_HDX_7/thor)

1 - select device | r - rescan | q - quit > [ 13.176669] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x255d7f350a7, max_idle_ns: 440795315188 ns

[ 13.266215] clocksource: Switched to clocksource tsc

1

Forging unlock image for the device (D0FBA0A034940HN0)

0x11534db7c8

ok

Checking bootloader for the device (D0FBA0A034940HN0)

remote object '/data/local/tmp/aboot.img' does not exist

Not quite as expected, but proceeding anyway ...

Rebooting the device (D0FBA0A034940HN0) to the bootloader

ok

Waiting until the [fastboot] prompt appears on the device (D0FBA0A034940HN0)

[ 42.001384] usb 1-1: USB disconnect, device number 2

[ 46.335499] usb 1-1: new full-speed USB device number 3 using ohci-pci

[ 46.948941] usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x81 has invalid maxpacket 512, setting to 64

[ 47.140958] usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x1 has invalid maxpacket 512, setting to 64

[ 47.213249] usb 1-1: New USB device found, idVendor=1949, idProduct=000c

[ 47.275501] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

[ 47.277363] usb 1-1: Product: Android

[ 47.278949] usb 1-1: Manufacturer: Google

[ 47.279582] usb 1-1: SerialNumber: D0FBA0A034940HN0

ok

Flashing unlock image to the device (D0FBA0A034940HN0)

target reported max download size of 536870912 bytes

sending 'unlock' (0 KB)...

OKAY [ 0.091s]

writing 'unlock'...

FAILED (remote: Unlock code is NOT correct)

finished. total time: 0.148s

Shutting down..

[ 49.535473] ACPI: Preparing to enter system sleep state S5

[ 49.698429] reboot: Power down