[Android Q&A, Help & Troubleshooting] biorpg:
Use fastboot to flash the stock ROM instead of Intel flash tool. (If you know what you're doing, just read the part in blue below.)

fastboot is for Android devices, whether they have Qualcomm or Intel processors. Using Intel Flash tool is more akin to using Qualcomm's QPST for flashing, which is also something that should only be attempted

after trying fastboot. The Intel flash tool expects the .zip file to be in a format such as a Chuwi ROM with Windows is. Intel Flash tool unfortunately doesn't expect the .zip to be in the Android format like Acer's stock

ROM "AV0L0-something.zip" is.

With the tablet off, and plugged into your computer, hold both volume buttons and power it on. (You probably already knew this step, but here just in case :o)

It will vibrate longer than it usually does when turning on.

The screen should indicate that the device is in download, or "dnx" mode.

Open a command prompt in administrator mode,(the title of the window should say "Administrator: Windows Command Prompt" or "Administrator: <current directory>")

Type:

fastboot

If command not found, then either copy fastboot.exe into System32, or add the path it is in to your PATH variable, or simply navigate to its directory within the command prompt.

If you're not familiar with the PATH variable, you can just shift+right-click on fastboot.exe, click "Copy Path" and then paste it into the command prompt to use it's full path in place of simply "fastboot".

Once you're able to type "fastboot" or paste the full path and press enter and it returns the fastboot help message, type:

fastboot devices

this will either return a single line containing your device's serial number, or it will return nothing at all

If you see a serial number, you're in business.

(make sure the tablet is not low on battery before you continue):

Type:

This should initiate a full reflashing of the stock ROM. The tablet will reboot a couple times, you should hear/feel an even longer vibration during the process, do not touch it or unplug it from the computer until it is at the initial Google device setup screen waiting for your input.

Note that this full reflashing will also overwrite TWRP with the stock recovery.

if "fastboot devices" returns nothing at all, and also doesn't say "command not found" then do the following:

open device manager on computer, find the tablet's driver (may be under portable devices, or COM ports. sometimes under USB.)

if you can't find it, look for an "unknown device" with a yellow exclamation mark on it. If you see that, then you may not have had the driver installed in the first place. To verify, unplug the tablet from the computer

and see if the unknown device disappears from device manager.

If you were able to find the tablet in device manager, then right click and "Uninstall Device" and be sure to check the box to uninstall the driver software as well before clicking OK.

Then, unplug the tablet from your computer if you haven't already.

Download the latest driver from the same place on Acer's website that you downloaded the stock ROM from. Install the driver and restart your computer if it says it needs to.

Afterward, ensure the tablet is off and try the steps above again.