iTunes could not connect to this iPad. The value is missing.

You'll want to plug the iPad in first to you computer, and then press the home button and power button at the same time until the screen goes black. 2 seconds after the screen goes black, let go of the power button, but keep holding the home button until iTunes recognizes the iPad in recovery mode. This is called DFU mode. Unfortunately if the iPad is disabled, a complete restore is the only option. I hope it's backed up somewhere.

I did the above steps. iTunes recognized the recovery mode, and started downloading the new software. However, after ipad reboot, i am still getting the same message "iTunes could not connect to iPad. The value is missing"

But it keeps saying this and won’t restore

so what you're saying is that Android is not secure and allows users to easily bypass a passcode? That alone is reason enough for schools NOT to use Android. Not to mention most of the apps your kid has probably aren't even available on Android. Perhaps you should be upset at the real issue - your kid forgot their passcode, so that's where the blame should be placed. Also, it does not take an entire weekend to restore a device! Troll...

You sir, are a God amongst men!!! Thank you so much! Ive been on with Apple support 4 times, and read every forum I could dig up.

The key is to continue holding only that home button during the restart.

Great advice! Thanks so much

Restarting the iPad is the right idea, but you should also re-launch iTunes, or just restart your computer.

Restart your iPhone, iPad, or iPod touch - Apple Support

If that doesn't do it, you might have to Restore your device from a backup. If backing up via iTunes, make sure it's an Encrypted backup.

Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

https://www.tenorshare.com/itunes-tips/fix-itunes-could-not-connect-to-iphone-th e-value-is-missing.html

Restore iOS Device in DFU Mode

If iPhone won't connect to iTunes and says value is missing, you can put the device into DFU mode first. Here is what you need to do.

• 1. Shut down your device completely and connect with a computer.
• 2. Hold down the Power and Home button for about 10 seconds.
  On iPhone 7/8/8 Plus, replace the Home button with Volume Down button.
  On iPhone X, it’s Side button and Volume Down button.
• 3.Let go the Power button but still keep holding the other button for 3 seconds. If a message pops up saying iTunes has detect your device in recovery mode, which means you are in DFU mode now.

When iTunes successfully recognize your iPhone or iPad, go ahead and continue what you need do in iTunes.

My kids disabled his iPad on which he has a lot of school apps, now due to unflexible apple OS we will have to waste our entire weekend reinstalling the iPad. I wish school has given us the option to go with Android !

Exactly how would you restore if your Ipad is locked and you cannot connect to itunes????

thank you....thank you ...thank you totally ready to throw it off a balcony, been at this for 3 hours

Pressing the home button and releasing the power button 2 seconds after the screen goes black did the trick! Thank you thank you thank you!

Thanks. Your reply and solution clinched it!

i tried that a few times but it didnt work. it kept on powering off and rebooting then turning back on. how long do i need to hold home for it to work?

Thank you. If finally worked and our I Pad Pro is back in business.

Oh my goodness! Yes a God amongst men....thank you, thank you, thank you! The gold......was holding the home key down while start up was happening!!!! I'm smiling now....