This worked fine, however since my WiFi was quite slow I did an update of all VMs including dom0 (I know, i probably could have skipped dom0 what I also will do in future).
After that Qubes OS was unable to start. After the disk password it is stuck on black screen or in the terminal. There were a lot of errors where I don't know which may be relevant, I remember a lot of APIC_ERROR but there was definitely more.
Next I tried to install a fresh Qubes OS 4 RC1 in the exact same manner I did with the 3.2. This never makes it to the graphical install screen and is stuck in a plain black screen after I hit install from the boot menu (which loads correctly).
I'll simply installed 3.2 again and won't update dom0 so I guess I will be fine. However is this kind of problem known? Is it related to Fedora 25 or XEN? And can it be worked around? (Afterall having a more recent software and drives still could be nice ;-))
Thanks in advance