iOS: Wrong passcode results in red disabled screen

For information on configuring and using a passcode, see iOS: Understanding passcodes.

Note that if you enter the wrong passcode you'll see a screen that says "Wrong Passcode, try again."

If you enter the wrong passcode too many times, you'll see a message that says "[Device] is disabled" and to try again later:

If you repeatedly enter the wrong passcode, your iPhone, iPad, or iPod touch will be disabled for longer intervals before you can try again. After too many unsuccessful attempts, you won't be able to try again until you connect it to the computer with which you last synced it.

Note: You can configure your device to erase itself after ten consecutive incorrect password attempts. This setting is off by default. It can be turned on by tapping Settings > General > Passcode Lock.

If you cannot remember the passcode, you will need to restore your device using the computer with which you last synced it. This allows you to reset your passcode and resync the data from the device (or restore from a backup). If you restore on a different computer that was never synced with the device, you will be able to unlock the device for use and remove the passcode, but your data will not be present. Refer to Updating and restoring iPhone, iPad and iPod touch software.

If the issue continues after updating and restoring your device, refer to this document.