Error starting Virtual machines on virtualbox - Yosemite

[LinkRaider]

I obviously meant a link from a website that you already tested or something like that.

[LinkRaider]

So, after a lottttt of tests I found out what the problem is. The vt -x / amd -v must be off. If I disable that option and try with a x86 host, the machine works

The problem is that option must be enabled in order to run x64 hosts, so every time I try to launch one 64 bits machine, the problem arises.

If I do uname -m I get the output: x86_64
This seems correct.

Do you have any idea how can I run x64 hosts on this? Bear in mind that I reinstalled the machine with the latest Yosemite version, and my Virtualbox version is 4.3.20.

Does anyone have an idea about this? There's seem to be a bug in my car, he can't cross all the roads

[loukingjr]

that is not your problem. 32bit guests run just fine with VT-x enabled and 64bit guests require it be enabled.

I'm getting the feeling you are trying to run VirtualBox inside a Yosemite host running VMWare Fusion or some other hypervisor.

Seeing you still haven't attached a log for any guest and not much useful info is forthcoming I will let someone else take over.

[mpack]

00:00:36.497176 ERROR [COM]: aRC=VBOX_E_INVALID_VM_STATE (0x80bb0002) aIID={8ab7c520-2442-4b66-8d74-4ff1e195d2b6} aComponent={Console} aText={Invalid machine state GuruMeditation when checking if the guest entered the ACPI mode)}, preserve=false
00:00:38.089888 Console::powerDown(): A request to power off the VM has been issued (mMachineState=Stopping, InUninit=0)

It does look like an interaction with some other software which is (or was) using VT-x, perhaps incorrectly. That could be other VM software, system level debuggers, AV etc. Only the OP can know what other software is present.

[loukingjr]

The OP did have VMWare Fusion installed but said he uninstalled it. There aren't many AV products for Macs and I doubt they would be using VT-x. As far as system level debuggers, it doesn't strike me as something the OP would use. Beats me.

FWIW, I have VMWare Fusion installed along with VirtualBox and as long as they are not running at the same time they don't interfere with each other.