Hi @Vi_pro, I am sorry to hear about this.
Have you been able to restart your phone in safe mode to see if you receive the same error message there? All apps downloaded from Play Store is temporarily deactivated while in safe mode and by doing this you can see if this behaviour is caused by a downloaded app. For more information on safe mode and how to use it, click here.
If the same error message appears in safe mode, I suggest that you try to repair the software on the phone using a computer and Xperia Companion. Keep in mind that a software repair will erase all user data from the phone, so it is advised to do a backup of your user data before proceeding with the repair.
Try these measures and let me know how it goes!
