For this case, it is not the system failure.It is because you root your tablet and deleted Maxisys App,that's why the
Factory Reset will not work.
If this is the case, I think you need the installation file - Maxisys.apk. to re-install it to your tablet. But for confidential purpose, usually it is not allowed to send the Maxisys.apk to customer directly. I will come back to your email tomorrow.