VMs won't start after upgarde to 5.1 NS_ERROR_FAILURE (0x80004005)

[wyrdlg]

Dear All,
so thats what happened and is:

I start my VM as usual by "VBoxManage startvm MCFTBIE --type headless" and then:

Waiting for VM "MCFTBIE" to power on...
VBoxManage: error: The virtual machine 'MCFTBIE' has terminated unexpectedly during startup with exit code 1 (0x1)
VBoxManage: error: Details: code NS_ERROR_FAILURE (0x80004005), component MachineWrap, interface IMachine

This happens to both my VMs (1 Windows, 1 Linux) after I updated to Oracle VM VirtualBox Version 5.1.0
Primarily uninstalled 4.x
Guest (4 cores 8GB ram) and Host (8 cores 16GB ram) both Ubuntu Server 16.04 LTS with an 64 bits
All running Headless

Thanks for all your help in advance!

Here's some data:

VBoxManage list extpacks
Extension Packs: 1
Pack no. 0: Oracle VM VirtualBox Extension Pack
Version: 5.1.0
Revision: 108711
Edition:
Description: USB 2.0 and USB 3.0 Host Controller, Host Webcam, VirtualBox RDP, PXE ROM, Disk Encryption.
VRDE Module: VBoxVRDP
Usable: true
Why unusable:

VBoxManage showvminfo MCFTBIE --details
Name: MCFTBIE
Groups: /
Guest OS: Ubuntu (64-bit)
UUID: c99cf98b-1cc1-459b-bccf-9964755f6837
Config file: /media/daten/vm/MCFTBIE/MCFTBIE.vbox
Snapshot folder: /media/daten/vm/MCFTBIE/Snapshots
Log folder: /media/daten/vm/MCFTBIE/Logs
Hardware UUID: c99cf98b-1cc1-459b-bccf-9964755f6837
Memory size: 8192MB
Page Fusion: off
VRAM size: 12MB
CPU exec cap: 100%
HPET: off
Chipset: piix3
Firmware: BIOS
Number of CPUs: 4
PAE: on
Long Mode: on
Triple Fault Reset: off
APIC: on
X2APIC: off
CPUID Portability Level: 0
CPUID overrides: None
Boot menu mode: message and menu
Boot Device (1): DVD
Boot Device (2): HardDisk
Boot Device (3): HardDisk
Boot Device (4): Not Assigned
ACPI: on
IOAPIC: on
BIOS APIC mode: APIC
Time offset: 0ms
RTC: local time
Hardw. virt.ext: on
Nested Paging: on
Large Pages: off
VT-x VPID: on
VT-x unr. exec.: on
Paravirt. Provider: Default
Effective Paravirt. Provider: KVM
State: powered off (since 2016-07-21T08:36:51.000000000)
Monitor count: 1
3D Acceleration: off
2D Video Acceleration: off
Teleporter Enabled: off
Teleporter Port: 0
Teleporter Address:
Teleporter Password:
Tracing Enabled: off
Allow Tracing to Access VM: off
Tracing Configuration:
Autostart Enabled: off
Autostart Delay: 0
Default Frontend:
Storage Controller Name (0): SATA Controller
Storage Controller Type (0): IntelAhci
Storage Controller Instance Number (0): 0
Storage Controller Max Port Count (0): 30
Storage Controller Port Count (0): 30
Storage Controller Bootable (0): on
Storage Controller Name (1): IDE Controller
Storage Controller Type (1): PIIX4
Storage Controller Instance Number (1): 0
Storage Controller Max Port Count (1): 2
Storage Controller Port Count (1): 2
Storage Controller Bootable (1): on
SATA Controller (0, 0): /media/daten/vm/MCFTBIE/MCFTBIE.vdi (UUID: 5839df14-b29e-426b-9aeb-b9ae510fd51d)
IDE Controller (0, 0): Empty
NIC 1: MAC: 080027D741BF, Attachment: Bridged Interface 'enp0s8', Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
NIC 2: disabled
NIC 3: disabled
NIC 4: disabled
NIC 5: disabled
NIC 6: disabled
NIC 7: disabled
NIC 8: disabled
Pointing Device: PS/2 Mouse
Keyboard Device: PS/2 Keyboard
UART 1: disabled
UART 2: disabled
UART 3: disabled
UART 4: disabled
LPT 1: disabled
LPT 2: disabled
Audio: disabled
Clipboard Mode: Bidirectional
Drag and drop Mode: Bidirectional
VRDE: enabled (Address 0.0.0.0, Ports 3389, MultiConn: off, ReuseSingleConn: off, Authentication type: null)
Video redirection: disabled
VRDE property: TCP/Ports = "3389"
VRDE property: TCP/Address = <not set>
VRDE property: VideoChannel/Enabled = <not set>
VRDE property: VideoChannel/Quality = <not set>
VRDE property: VideoChannel/DownscaleProtection = <not set>
VRDE property: Client/DisableDisplay = <not set>
VRDE property: Client/DisableInput = <not set>
VRDE property: Client/DisableAudio = <not set>
VRDE property: Client/DisableUSB = <not set>
VRDE property: Client/DisableClipboard = <not set>
VRDE property: Client/DisableUpstreamAudio = <not set>
VRDE property: Client/DisableRDPDR = <not set>
VRDE property: H3DRedirect/Enabled = <not set>
VRDE property: Security/Method = <not set>
VRDE property: Security/ServerCertificate = <not set>
VRDE property: Security/ServerPrivateKey = <not set>
VRDE property: Security/CACertificate = <not set>
VRDE property: Audio/RateCorrectionMode = <not set>
VRDE property: Audio/LogPath = <not set>
USB: disabled
EHCI: disabled
XHCI: disabled

USB Device Filters:

<none>

Bandwidth groups: <none>

Shared folders: <none>

Video capturing: not active
Capture screens: 0
Capture file: /media/daten/vm/MCFTBIE/MCFTBIE.webm
Capture dimensions: 1024x768
Capture rate: 512 kbps
Capture FPS: 25

Guest:

Configured memory balloon size: 0 MB

[hideo]

Hello,

I get the same error on Fedora23.

[hideo]

Hello,

There is another version Oracle_VM_VirtualBox_Extension_Pack-5.1.2-108956.vbox-extpack, but still failed when i try to install, with the same message.

[socratis]

Install the newly released VirtualBox 5.1.2 with a matching extension pack, i.e. the same version as VirtualBox. They have to match. From the official site: https://www.virtualbox.org/wiki/Downloads