I upgraded iPhone 4s to latest ios version 9 to 9.3, I lost my wifi connection, its keeping say: incorrect password
I followed all suggested ways like reset network setting, restore factory settings, restore firmware, turn wifi off in icloud setting, use hair dryer to hit it up, or put in refrigerator, change DNS to Google, use auto proxy, off proxy, turn antivirus off, firewall off, upgrade latest version of iTune, change router security encryption WPA/WPA2,
manually enter SSID and password and DNS, all provided ways I did but it is still same pop message: INCORRECT PASSWORD
So, however I know there’s no way to downgrade ios to lowest version cause of error 3194, but I also tried to change and remove Apple IP address in hosts file in the root of : Windows\System32\drivers\etc
So, I’m gonna downgrade ios to 8.4.1 cause I didn’t have problem that time.
I called apple customer service, they checked my iphone through diagnostic, they informed me that there’s no problem with hardware, so even they also couldn’t solve the problem. I also went to apple customer service directly, they also couldn’t solve it.
So here’s my question.
According to apple customer service informed me that there’s no problem with hardware, so it means the problem is related to ios 9 that’s why I lost my wifi connection.
How to downgrade it? How to solve it based on all above mentioned matters.
Thanks in advance