Xperia Z5 Premium "System UI has stopped" when try to select wifi

[xperia_z5p]

Started 2 days ago. Tried to select wifi from pull-down taskbar. Immediately "System UI has stopped" and I have to select "Close app". Then the screen went black for few seconds before coming back on. When coming back on, message "Pin required for additional security" comes up (I use pin for screen lock).

When trying to select wifi from Settings > Wifi instead, it crashed and message "Settings has stopped" comes up. I have to select "Restart app". "Settings" page comes back on. Tried to select "Wifi" and "Settings keeps stopping" and I would then have to choose "Close app".

So annoying. Meaning I will never ever connect to a new wifi unless it was a previously connected/saved wifi.

Rebooted to safe mode, Tried and still the exact thing happens, both from pull-down task bar and Settings app.

What should I do?

Here are the deets.

Sony Xperia Z5 Premium

Model: E6853

Android: 7.1.1

[Uliwooly]

@xperia_z5p

Since you experience the same issue even in safe mode you might want to consider repairing the phone with XC 

Xperia Companion (XC)

Software Repair Guide

Alternatives on How to backup Xperias

http://talk.sonymobile.com/thread/36355

[xperia_z5p1]

Thanks. Sorry for late reply because it took me this long to do this process. Done it twice. Great at first but saw the problem again. Still don't know how/why but each time I restore back up after repair, the problem comes back. So now trying to figure out how to back up phone before doing the repair one more time but without “saving that error" just to be added back again.

[Wusch]

Have you found a solution? I have the same problem..