Every steps work normally until it extracting firmware file to restore to 9.3.3/9.2.1 (I tried both fw).
After veryfing restore, the Terminal show:

ERROR: Unable to successfully restore device

Then told me to restart the restore but it never work.

I can restore to iOS 10 untether with turdus_m3rula seperately. it only stuck in a999 terminal.
How can I fix it ?