error code 4016

I need suggestion,

1) I have found that "WiFi" couldn't be turn on anymore (light grey appearance!) after relaized that torch application was deleted, I have reinstalled it back but nothing happend, after open flash light for a while when 5% power left ... nothing happend, retore ... nothing happened! I CANNOT USE WIFI via my iPhone anymore which is taken about a month alredy! it was completely DEAD

2) Now, Nethier restore nor upgrade iOs applicable.

3) Error Code 4016

Could you please give me an advice how to fix?

MLN THX!