[Fuhu Nabi 2] snailman153624:
I found a simpler solution

I had the exact same issue (Fuhu servers shutdown, I didn't know this...performed a factory reset...locked out of tablet), but on a Nabi Elev-8 tablet (8" 1280x800, Octa-core Snapdragon processor, 32GB storage, NFC, Wifi, etc.).

I found a backdoor to get into the Android Settings menu, and enable developer options, and thus enable ADB. No TWRP/root required. With ADB, I was able to disable a bunch of Fuhu packages, which got around this problem, and got rid of a bunch of bloatware to boot. I posted this on stackoverflow, but cannot post a link. But here's the details in case it helps someone else:

Although the initial setup doesn't let you exit it, I found that if I hit the power button while in the WiFi setup, when I turn it back on it shows the Nabi lock screen. Rather than unlocking the tablet, you can actually get into the Android setup menu from the lock screen!

In there, I was able to enable developer options (yes!!!):

Settings -> About Tablet -> Tap on "Build number" over and over until it enables developer options

NOTE, tapping on other fields repeatedly also pulls up other hidden gems, like a hardware test, and an Android Easter Egg. Next, go to:

Settings -> Developer options

and enable "USB debugging"

Plug in your USB cable, and install "adb" (android debugger) on your PC. I'm using Arch Linux, so:

sudo pacman -S adb

did the trick. You might need to accept some RSA key security prompts on the tablet to connect to the PC. Now, onto the fun stuff...

The tablet is NOT rooted...so you can't remove any packages. However, you can disable them! I extracted a complete list of the "fuhu" packages, then tried disabling them one at a time. I found that by disabling most (except for a few exceptions) I was able to get rid of most of the bloatware, and kill the initial setup!

Use this command to launch an adb shell on the tablet:

adb shell

Then disable the packages with these commands:

pm hide com.fuhu.nabisystemupdatechecker
pm hide com.fuhu.nabimode
pm hide com.fuhu.nabipass
pm hide com.fuhu.nabi.systemupdate
pm hide com.fuhu.nabiintentmanager
pm hide com.fuhu.nabiui
pm hide com.fuhu.nabidreamtabus.download
pm hide com.fuhu.foozkids.webs.v2
pm hide com.fuhu.nabi.updater
pm hide com.fuhu.appzone.v2
pm hide com.fuhu.addapps.v2
pm hide com.fuhu.drmmanager
pm hide com.fuhu.nabiaccountmanager
pm hide com.fuhu.foozkids.videos.v2
pm hide com.fuhu.nabi.cloud
pm hide com.fuhu.nabi.radio
pm hide com.fuhu.foozkids.nabi.activity
pm hide com.fuhu.foozkids.crafts.v2
pm hide com.fuhu.foozkids.books.v2
pm hide com.fuhu.gallery
pm hide com.fuhu.dashboard
pm hide com.fuhu.timecontrol
pm hide com.fuhu.nabi_video
pm hide com.fuhu.nabi.chores
pm hide com.fuhu.nabiconnect
pm hide com.fuhu.wings.wooshu
pm hide com.fuhu.nabi.sync
pm hide com.fuhu.nabinotification
pm hide com.fuhu.nabidemosetup
pm hide com.fuhu.nabiWeb
pm hide com.fuhu.nabisnm
pm hide com.fuhu.foozkid.univ.v2

You no longer will have the parental controls (never used them anyway), but "Parent Mode" will still be there (you can't get rid of this...the Android UI crashes if you disable it). I got rid of all of the fuhu apps that didn't work, with the exception of "nabi Player" (some sort of media player)...I couldn't find its package. It just throws an error if you try to use it.

The tablet also throws a UI error when you do a cold boot. I just hit OK, and it works normally. All of the Android stuff works fine, including Play Store, Wifi, Chrome, etc.

If you want to see what packages are installed (but enabled), in the adb shell:

pm list packages

To include disabled packages:

pm list packages -u

In Linux/bash (outside of adb), to see a list of only disabled packages, you can use diff and grep:

diff <(adb shell pm list packages -u | grep -i fuhu) <(adb shell pm list packages | grep -i fuhu)

I hope this helps someone! I was able to unbrick my kids' tablets, and they also run a bit faster with a bunch of bloatware disabled.