Well, other people, other ways of thinking. That’s what makes us human and what enables the whole species to develop 
Playing around with search input at the top level could have let you find this.
And if you do not feel comfortable in an english forum, there is a german forum as well.
Last but not least: Kein Backup, kein Mitleid. (no backup, no pity). I know it is harsh, but it is the truth. Always ensure you can go back to what you have BEFORE doing upgrades. And test what you need to do to apply the backups in order to revert to a former state. The backup files are useless without the knowledge how to use them in case…