Miracle 2.26 failed write flash SPD 7731G ?

My evercoss AT7J+ with SPD 7731G normally operated, just full of bloatware & virus.
Miracle AV failed to delete this apk. So i write flash this tablet with rom from evercoss support web.
Till 82% write of system, write processing was halt and get this error.

After failed, my tablet is dead and not detect anymore on my laptop.
Whats wrong with this, and how to recover?