Cubase 9 update problem

I downloaded cubase 9 update and installed it over cubase 8.5 and since then I have lost some files. All the cubase documentation files are gone. When I click on help within cubase, there is nothing.
I have tried searching my computer for the documentation pdf files but they no longer exist. Also, all my channel insert settings are gone. Why has this happened ?
I have lost all those files which i can never get back and have to start all over again. Where can i get all the cubase documentation files from ? I have searched here on Steinberg website but can’t find anything.
Can someone please help.