cannot run any guest above VirtualBox-4.1.28-89849-Win

[realam]

hello

i just recently installed windows 8 x64 in a virtualbox 41 (VirtualBox-4.1.28-89849-Win to be precise), because i use VirtualKD a lot and 4.2+ support for it is not yet ready.
everything went fine until i installed the guest additions, as everything started to flicker, mainly when metro ui elements were active.
i have read that vbox 4.1 support is not really good for windows 8, so i went and installed the latest virtualbox (VirtualBox-4.3.0-89960-Win).

The problem is that no virtual machine seems to boot with this version, even created a minimalt xp machine, just to try to boot, but same error:

Code: Select all

Failed to open a session for the virtual machine win8_x64.

The version of the device registration structure is unknown to this VBox version. Either mixing incompatible versions or the structure isn't correctly initialized. (VERR_PDM_UNKNOWN_DEVREG_VERSION).

Result Code: E_FAIL (0x80004005)
Component: Console
Interface: IConsole {8ab7c520-2442-4b66-8d74-4ff1e195d2b6}

tried VirtualBox-4.2.18-88781 too, but the effect was the same.
needless to say that i had installed the correct extension pack all the time.

my host is a Windows 7 x64, running on a core i7.
as a sidenote i have a vmware 7.1.2 installed and used (obviously not running when i try to run virtualbox), but this so far did not affect virtualbox 4.1.

help would be really appreciated.

[frank]

Some outdated device. Do you have VirtualKD installed? A VBox.log would show it.