[Miscellaneous Android Development] martyfender:
[MENTION=8203588]TJMartin55[/MENTION]

What you did is not very clear. Why didn't you follow my instructions in the OP, instead of these Droid School instructions?

Is this the files you downloaded for your tablet, from the link in the OP: unsigned-211.img.zip?

In order to unencrypt the tablet, the userdata partition has to be erased to create new, unencrypted data partition. Did you flash SuperSu also? If you flashed it after flashing my modified boot.img it would have disabled encrypion and dm-verity, assuming you did a factory reset after or deleted data in twrp or userdata with fastboot commands. Can you boot the tablet into fastboot/bootloader mode? From power off, by holding the power button about 5-10 seconds: hold the volume down and the power button at the same time, until it boots to the fastboot/bootloader screen with the yellow/green android guy on his side. When plugged into your PC you should issue:

fastboot devices

enter key

to see your device serial # listed

fastboot flashing unlock

hit the enter key will unlock the bootloader

fastboot flash boot unsigned-211.img

hit enter to flash my modified boot.img, unless you renamed it to the above in the commands you listed: fastboot flash boot boot.img

fastboot boot Ares8A_recovery_twrp.img

will temp boot TWRP that is on your PC in the adb and fastboot folder.

In TWRP click install, navigate to the SuperSU-v2.82-201705271822.zip and swipe to flash supersu. This supersu.zip must be on the external sd card or internal tablet storage for this to work, though.

I always recommend opening your command windows this way:

In the adb folder blank spot, shift, right click to open a command prompt here.

Those above Droid school instructions are missing a lot of steps and you usually type those commands in fastboot/bootloader mode and not in TWRP.

By thumb drive, do you really mean the microSD card inserted into the device? Using a thumb drive with this device would require a USB OTG cable, I believe.

Prior to doing what you did, did you enable developer options on the tablet and in those options, check enable USB debugging and enable OEM unlocking? Reread the Op, especially my updated instructions at the end of the OP that I link to. If the tablet does boot to TWRP it should be very clear as you will see: Team Win Recovery Project at the top of the page in blue and the rest of the page is black with TWRP option tiles in grey like install, wipe, backup, retore, mount, settings, advanced and reboot. Attached is a screen shot I grabbed from the web of another version of TWRP.

What drivers, adb and fastboot did you install? You need the Intel drivers I provide a link for and the linked adb and fastboot files for Windows. Those linked in my OP? If not, that is the place I would start along with my tests to confirm that it is working. The Windows device manager will show intel adb device when the tablet is booted normally and should show intel fastboot device when booted in fastboot/bootloader mode and connected to the pc.

The next step is enabling developer options and USB debugging. Of course now that you can't boot normally, that is hard to do the normal way.

Was there a reason why you would want to disable encryption alone and not also root the device? My methods do work when rooting. Also, If you are using apps that detect root, you can root with Magisk and the device will pass safety net and playstore certification, unlike SuperSU.