[Nexus 9 Q&A, Help & Troubleshooting] TheShryke:
Hi,

I followed this article -> phandroid DOT com/2014/11/05/how-to-root-nexus-9/ (Sorry, new account, can't link) to the letter, and everything seemed to go well, until the last step where I ran "fastboot reboot" which returned "error: device not found" I thought nothing of this as there was a reboot option on the devices screen, so I rebooted, I get the google logo, followed by the four orbs, then it says "Optimising app x of 99" once this is done, its back to the orbs again and it just repeats.

I tried restoring to factory defaults from the recovery menu, that did nothing, then sometime after I noticed I actually cant turn the device off any more, if I hold the power button it turns off, but reboots instantly. I tried going through the steps again, but no luck, the only change was that I didn't have the error at the end, and the first Optimising dialogue said 104 apps, not 99, but all the rest afterwards have said 99.

I'm not sure what do do from here, any advice?

Here's my cmd output:

## First attempt ##

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>adb
reboot bootloader

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot oem unlock
...
(bootloader) ability is 1
(bootloader) RUU_frame_buffer_enable_flag=0
(bootloader) Start Verify: 0
(bootloader) [hboot query] query 24 is not implemented
(bootloader) [hboot query] query 24 is not implemented
(bootloader) Start Verify: 0
(bootloader) [hboot query] query 24 is not implemented
(bootloader) [hboot query] query 24 is not implemented
(bootloader) Unlock device successfully!
OKAY [ 23.489s]
finished. total time: 23.489s

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot boot inject.img
cannot load 'inject.img': No such file or directory

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot boot nexus9\inject.img
downloading 'boot.img'...
OKAY [ 0.783s]
booting...
OKAY [ 0.156s]
finished. total time: 0.939s

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot flash boot nexus9\patched.img
target reported max download size of 518205818 bytes
sending 'boot' (7830 KB)...
OKAY [ 0.541s]
writing 'boot'...
(bootloader) Device State : Unlocked
OKAY [ 0.798s]
finished. total time: 1.339s

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>adb
reboot
error: device not found

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>adb
reboot
error: device not found

## Second attempt ##

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot oem unlock
< waiting for device >
...
(bootloader) ability is 1
(bootloader) Device stete is unlock already
OKAY [ 0.141s]
finished. total time: 0.141s

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot boot inject.img
cannot load 'inject.img': No such file or directory

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot boot inject.img
downloading 'boot.img'...
OKAY [ 0.749s]
booting...
OKAY [ 0.158s]
finished. total time: 0.908s

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot flash boot patched.img
target reported max download size of 518205818 bytes
sending 'boot' (7830 KB)...
OKAY [ 0.539s]
writing 'boot'...
(bootloader) Device State : Unlocked
OKAY [ 0.787s]
finished. total time: 1.326s

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>fas
tboot reboot
rebooting...

finished. total time: 0.066s

C:\Development\Android\adt-bundle-windows-x86_64-20131030\sdk\platform-tools>