[Milhouse]

Hm, wasn't that easy at all.
Mainboard did not boot with old install, I had to do a new one. But when you're used to it, it's done quickly, so noc problem.

I suppose if your old motherboard supported only legacy BIOS and your new motherboard is using UEFI to boot then it will fail to boot the new motherboard. Most UEFI systems support legacy booting which should have worked but may not be your default (you'd need to configure this in your BIOS). Re-installing from scratch will create a UEFI compatible system.

But I recognized another Problem with saving deinterlacing settings when playing back something and using advanced settings xml.

What are you putting in advanced settings?

I told Kodi to use motion adaptive deinterlacing when playing back something, but after a channel switch for example, the settings are back to bob.
Settings don't get saved.

After changing deinterlace did you click on "Set as default for all media"?

When I delete my advanced settings.xml, the settings get saved.

Is this a known bug?

Not that I'm aware of. You should probably open a trac ticket.