Android Lenovo Tablet Update Error Message

I am not able to turn off my device or boot it up. The error message is this while installing system update:

"Opening update package...
Signature verification failed
Installation aborted."

It keeps flashing this message every few seconds. Not sure how to fix this issue, happened after I did a system update.

from Android Authority Forums http://ift.tt/2xZWLz0
via IFTTT