Virtual Box Black Sccreen Flashing Cursor

paynod · Post by **paynod** » 8. Jul 2019, 23:16

Hi, I've been running an installation of Ubuntu 18.04 on my VirtualBox VM. After a number of weeks not using VirtualBox I booted it up only to be taken to a black screen with a flashing cursor. I can boot into grub where it say 'loading RAM disc'... Ultimately the screen hangs with a flashing cursor. I made sure that VT is checked in the Bios which seems the most common cause online. The problem persists if I try and install Ubuntu or Debian on a new VM. I've attached the log. I'm no expert but desperate to get this working again.

Thanks, Tim

Post by **scottgus1** » 9. Jul 2019, 00:24

00:00:03.115182 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:03.178331 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

Yep, 'tis the usual. Here's the usual advice:

socratis wrote:Look in the "Control Panel" » "Programs and Features" » "Turn Windows features on or off", and make sure that the none of the following are active (the list keeps getting bigger by the day):

Application Guard

Credential Guard

Device Guard

<any> * Guard

Containers

Hyper-V

Virtual Machine Platform

Windows Hypervisor Platform

Windows Sandbox

Windows Subsystem for Linux (WSL)
If that doesn't work, enter the following command:
bcdedit /set hypervisorlaunchtype off
followed by a cold boot, i.e. shut down the computer,.

paynod · Post by **paynod** » 9. Jul 2019, 23:28

Scott,
Solved, you have literally saved me from complete despair. What a legend!!! Great advice all working now. Thanks again, massively appreciate your time.

Tim

virtualbox.org