Opensuse Tumbleweed won't start on Virtualbox

After installing openSUSE-Tumbleweed-DVD-x86_64-Current.iso in Virtualbox i’m stuck on a text screen that flickers and won’t even boot into a terminal or graphical environment

Kernel 4.5.x currently in TW closed a kernel-memory hole that was apparently used by the VBox video driver prior to version 5.0.18.
So current Tumbleweed won’t boot on VBox versions up to 5.0.16 as installed.
Testing the upstream (from 5.0.18 version I had to add “iomem=relaxed 3” to the boot command line, login to console as root, install the 5.0.18 GuestAdditions in the guest Tumbleweed, reboot and I still use “iomem=relaxed” to boot.
See this for a related discussion.

The OpenSuse packaged version 5.0.18-211.1 available from the Virtualization repo should work as well, but I didn’t test yet.
A recent post suggests that choosing > System > Acceleration > Legacy in the Virtual Machine settings might help as well if booting fails with the default settings.

To use the LiveDVD version you should have better chances with KVM/QEMU or VMWare…