There was a new Beta-Bios yesterday (1.42). This solves the problem. I can now boot a standard Ubuntu 17.04 normally and with ACPI turned on. So far it also looks stable.
X299 ACPI Error: UEFI or Driver/Kernel bug?
There was a new Beta-Bios yesterday (1.42). This solves the problem. I can now boot a standard Ubuntu 17.04 normally and with ACPI turned on. So far it also looks stable.