If the keyboard stopped working after 8.1 update. It is most likely due to the system settings have been reset. The problem is most likely the filter key function. To fix this, disable the filter key and restart the device. For more details please visit this Trouble Shooting Page
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If the keyboard stopped working after 8.1 update. It is most likely due to the system settings have been reset. The problem is most likely the filter key function. To fix this, disable the filter key and restart the device. For more details please visit this https://www.ifixit.com/Wiki/Vaio_Tap_11_Troubleshooting#Section_Keyboard_stopped_responding
Heheheh gonna steal someone else's answer
If the keyboard stopped working after 8.1 update. It is most likely due to the system settings have been reset. The problem is most likely the filter key function. To fix this, disable the filter key and restart the device. For more details please visit this Trouble Shooting Page