Failed to open session for the virtual machineVT-x is not available (VERR_VMX_MO_VMX)E_FAIL (0x80004005)
VirtualBox failed to open session for the virtual machine
If VirtualBox VM is not opening or starting, then to fix this problem, you will need to undertake the following steps:
1] Open VirtualBox as administrator
Although administrator privilege is not mandatory by default, sometimes you might need to use that to fix this problem. If you have a desktop shortcut of VirtualBox and you use this shortcut to open this tool, you can right-click on the corresponding logo, and select Run as administrator. However, if you want to provide the admin permission to VirtualBox permanently, you need to follow these steps. Right-click on the desktop shortcut and go to Properties. After that, switch to the Compatibility tab.
Here you should find a checkbox saying Run this program as an administrator. Make a tick in that checkbox and click the OK button to save the change. However, if you do not have a desktop shortcut and you open VirtualBox from the Start menu, here is what you can do. You can search for VirtualBox, right-click on the exact search result, and select Run as administrator. Also, if you want to give admin permission to this Start menu button, the following steps will help you. Search for VirtualBox in the Taskbar search box, and select Open file location. Basically, you need to open the Startup folder in Windows computer and go to Oracle VM VirtualBox. After that, right-click on the Oracle VM VirtualBox icon, and go to Properties > Compatibility tab and select the Run this program as an administrator checkbox. After doing this, you should not get the problem as mentioned earlier. Fix: Raw-mode is unavailable courtesy of Hyper-V VirtualBox error.
2] Install platform package
The platform package helps VirtualBox to use various components with ease. If you haven’t installed it yet, you can head over to this page, and download the latest platform package for your OS.
3] Discard saved state
If you haven’t closed the VirtualBox or running the virtual machine properly, there is a chance of getting such an issue. Therefore, use the Discard Saved State option to kill all the running processes, and close the app immediately. Alternatively, you can select the virtual machine, and press Ctrl + J.
4] Reinstall VirtualBox
If none of the above suggestions helped you to fix the problem, the only solution is the reinstallation of VirtualBox. Do not forget to remove all the leftovers before installing it again. I hope these solutions will be helpful to you. Next, we will see what you can do if VirtualBox failed to register & open Hard Disk image file.
