[SOLVED] All cumulative Updates fail on Windows Server 2016

[Maxstar]

You're welcome! Glad to hear the issue has been resolved...

Do I find clear information in the CBS log, what packages are corrupt (the ones that you repaired / replaced with your SFCFix tool)?

Yes, but the CBS log is not only logfile to examine issues, see also the following public tutorials.
- Troubleshooting 0x800f081f / 0x800f0982 Error
- Troubleshooting Windows Update Log Errors

Where do you get right packages from, that you included in the SFCFix zips or in general if you identified one?

I'm running dozens of VM's (with snapshots / images for specific builds) which I can use as source for files, registry entrys etc..
I also use the Microsoft Update Catalog to download and unpack the *.MSU files to use as source. Currently I'm using an 2 TB HDD for unpacked updates.

How do you replace the packages without the SFCFix tool, can I just copy them over?
And how did you know which packages to set the right permissions and what are the right permission for these?

See the first link above, SFCFix will do that for you....