If LockDown Browser on your iPad opens and immediately crashes, the way to fix it is to uninstall and reinstall the app. Swiping away the app, updating the app, updating iOS, doing a home-power reset all do not fix this issue (at least not at the time of this writing).
iOS 11 Update: Just tested on iOS 11, and it stays in guided access mode after a reboot. Same with iOS 11.1.
Update: Just saw an iPad with 10.3.3 not get out of guided access mode after a reboot.
Just a quick observation based on testing:
If you're in Guided Access mode on an iPad running iOS 9.3.5 (say, an older model that can't install iOS 10 and above), and you do a forced reboot (hold home and power buttons until the Apple symbol appears), the device stays in Guided Access mode.
If, however, you're in Guided Access mode on an iPad running iOS 10 (and perhaps in future versions?) and do a forced reboot, the device gets out of Guided Access mode.
P.S. I was able to use this to help a student out who was stuck in Guided Access mode on an older iOS version—updated it to iOS 10, rebooted, and then the iPad was out of Guided Access mode, and a new Guided Access mode passcode could be set.
If you get an unknown error when restoring an iPad to factory settings and you know your iTunes is up to date and you don't have anything weird blocked on your firewall or web filter, it's likely the cable you're using. Apple has a full list of troubleshooting steps.
Just keep in mind that you may try several third-party cables that work fine in other instances or with other iPads, but if you have a particularly finicky iPad that refuses to be restored, make sure you use an official cable from Apple.
We had an iPad stuck in Connect to iTunes mode, and it refused to restore on multiple known-working (in other contexts) USB cables. Tried a download through iTunes. Tried a direct .ipsw download. The download was fine. It was just the restore that was finicky... until we tried an official Apple USB cable.
If you get an unspecified error when backing up your iOS device, there are a myriad of potential solutions (anything from looking for phantom apps on your iPhone/iPad to ignoring a local computer backup and going for an iCloud backup instead). Apple also has an official guide for things to try.
For the one user I saw experiencing this problem, none of those solutions helped. One simple thing did, though—using a different USB port on the laptop. The other USB port seemed to work fine for just about everything else, just not backing up the iPad to the computer via iTunes.
We've seen a couple of instances of students' Notability notes supposedly syncing to iCloud but really just disappearing. In these cases, we've looked closely with the students at their settings and checked both the iPad and their iCloud Drive account through a desktop/laptop computer, and—as far as we can tell—the missing Notability notes are stored somewhere in the iCloud but nowhere accessible by the user. It isn't on any of their devices or in their iCloud Drive.
Notability has its own official iCloud sync troubleshooting steps, but the easiest and most effective solution seems to be disabling iCloud sync altogether. Once you do that and choose to keep the notes on the iPad (instead of deleting them, even though they don't appear to exist), all the missing notes come back.
Google Drive is a better backup solution for Notability, because you can easily verify that the backups are occurring (they're either in the Google Drive Notability folder... or they're not). Just be sure to change the backup format from (the default) PDF to Notes.
We've come across a couple of iPads that give you an error 9 when you try to restore them to factory settings, usually after the iPad gets disabled or has some other funky state that cannot be recovered.
Apple has its own official help page for errors, but we didn't find that much use (no, security software wasn't blocking anything).
In one case, the iPad hadn't been updated in a long time and wasn't able to jump up versions to 9.2 from whatever it was (more details on this type of situation at iOS 4.3.5 error 9 when updating to 9.0.2), and Apple stopped signing older .ipsw files, so you can't even manually download those and use those as intermediate updates to the final one.
In another case, it was simply a bad USB cable... or a perfectly fine USB cable for charging and general file transfers but apparently not good enough to do a factory restore on. I'd say for this type of recovery it's worth trying to find the newest, shiniest iPad/iPhone cable you can find.
If you're using Google Apps for Education and add a Google account to Mails, Contacts, Calendars in iOS, you may notice only your primary calendars (and not "other calendars") showing up on your iPhone or iPad's Calendar app.
If that happens, just visit www.google.com/calendar/syncselect while logged into your GAFE account, and then check the box next to the calendar you want synced. That's it!
If you have a user with a bunch of apps to update in the iOS App Store, but tapping the Update button opens the app instead of updating the app, check to make sure her iOS is up to date.
For example, if you have a lot of pending app updates and are still on iOS 7, you may not be able to update them until you upgrade to iOS 8. I'm not sure why Apple doesn't tell you that (there should be an error message "You cannot update this app until you upgrade to the latest version of iOS" with a link to Settings to do the iOS upgrade) instead of just opening the app.
Just a note in case anyone else has users with this issue (and a grayed-out Update All button).
These instructions work for iOS 8 (tested on both an iPhone and an iPad) using Ubuntu 14.04 (Trusty) and Ubuntu 15.04 (Vivid). The instructions will still likely work in other versions of iOS and Ubuntu, but your mileage may vary.
What's the problem?
If you take pictures with your iPhone or iPad and then plug your phone into your Mac, Photos (previously iPhoto) will import the pictures you took on your iOS device. It will not, however, easily allow you to copy random other photos that happen to be on your iOS device.
We recently had a user come in with an iPhone that had some pictures transferred from another computer with these pictures no longer living anywhere else, and so the user wanted the pictures backed up. Photos and iPhoto do not recognize and import random other photos that weren't taken with the camera.
There are plenty of paid-for utilities you can download that will allow you to copy photos and music off an iPhone or iPad, but if you'd rather save the money for other purchases, here's a little workaround that's cost-free.
Get Ubuntu Linux
Really, you can use any Linux distribution, since libimobiledevice is available for any Linux distribution, but we'll use Ubuntu for this example (and, handily, Ubuntu comes with libimobiledevice installed).
If you're a total Linux novice, you can read up quickly on how to get Ubuntu and how to make a bootable USB of Ubuntu. The instructions are a few years out of date, but the same basic procedure applies, and UNetbootin works on Windows and Mac OS X.
Using Ubuntu to rescue your photos (and music?) off your iPad or iPhone
If you're using Windows, make sure your BIOS or UEFI is set to boot to USB. If you're using Mac OS X, hold down the Option key at boot-up and then choose to boot from the USB stick (it may appear as just the word EFI).
You should get a boot menu similar to the following:
OEM install (for manufacturers)
Check disc for defects
Once the live session is booted, unlock your iPad or iPhone, and plug it into the computer that has live Ubuntu booted on it. Ubuntu will throw you an error saying it can't connect to the iOS device, but that's because you have to say on the iOS device that the computer is trusted. Once you say the computer is trusted, you should be able to select the device from the file manager (you do not need to physically unplug and then re-plug in your device).
For Windows, Ubuntu can write directly to the NTFS drive if you want to copy the photos or music there. For Mac, you'll need a USB stick or something else to copy the photos or music to.
This randomly happened after we set up a slew of iPads with the same email account (Gmail on Mail), and sending messages put the outgoing message into the Outbox with an error that the password is missing, with the options to Cancel or go to Settings. Going to Settings, though, offers no option to input a password.
You can see here other users frustrated with this problem:
GMAIL Accounts unusable after 8.3 update!
Some workarounds offered are to use the Gmail app or to add Gmail as an Exchange account (if you're using Google Apps and not a regular home Gmail account).
The workaround we employed was to double-click the home button, swipe away the Mail application, and then launch it up again. After a minute or so, there would be an error about the missing password again. This time, though, the prompt for Settings would take you to a screen to enter the password.
Very odd issue.