How to fix Android when developer options are not available for this user

I have an Android One with Oreo version and suddenly my Android rebooted and after that it started to behave strangely: 1) Notification section doesn't work. I can't see notifications from my apps and the arrow and the screw icon to settings access don't work. 2) As I can't access to the notification area, I can't enable Use USB to Transfer Files to access to my phone memory. 3) I can't access to developer mode (I before active it with a lot of taps over Build number). Clicking on developer options just shows developer options are not available to this user. 4) I can't update or install the apps on google play. They freeze on Download pending... message 5) Home and Switch buttons don't work. They light up and vibrate when I tap them but they do nothing. This issue is apparently related to a deconfiguration of user accounts. To fix it, you need re-setup the users. As you can't access to the user manager (you are in guest mode ...