Samsung Galaxy S4 can't turn on wifi, security settings automatically stuck on high

[kairajay]

When I try and turn on wifi the switch/button remains grey instead of turning green like all the other running functions/connections. I think bluetooth etc have the same problem, but I can get data and use my phone network otherwise.
Like I mentioned, the security settings are stuck on "high: blocks known and potential threats" - if I switch to "normal: blocks known threats" it goes back to high as soon as I leave the security settings page. Sometimes if I'm fast enough I can turn on wifi for a few seconds but not long enough to connect, then it's blocked again.
I've tried rebooting, taking out the battery/sim, backing up and doing a factory reset, changing up the device admins (knox, android device manager), and even rooting and renaming and later deleting a file (/system/etc/wifi/wpa_supplicant.conf) which was suggested in another thread and seemed to work for a lot of people, but not for me. Not sure where to go next, any ideas?

 

[B. Diddy]

Welcome to Android Central! Just guessing here, but try going to Settings>Security​ and Clear Credentials.

 

[kairajay]

Thanks for the suggestion, but that option is blacked out and I can't select it. Any ideas why?

 

[Larry_F]

Thanks for the suggestion, but that option is blacked out and I can't select it. Any ideas why?

My understanding is that some apps, and perhaps only when an account is setup for such an app, require that security setting. If you have such an app or such an account, perhaps one for accessing a Microsoft Exchange server or for NFC financial transactions, removing the account or unnstalling the app may allow you to clear credentials.

Larry