[Solved] Failed to open a session for the virtual machine

[Bazsl]

I upgraded my Win7 Pro 64 bit machine to Windows 10. I upgraded to VB 5.0.10. When I try to start any VM I get the error below. I then installed the latest pre-release build, 5.0.11 and get the same error. How can I fix this error? Note that I am a casual user of VB so I need the answer for dummies. Thanks.

Bill

Failed to open a session for the virtual machine

VT-x is not available (VERR_VMX_NO_VMX).

Result Code:
E_FAIL (0x80004005)
Component:
ConsoleWrap
Interface:
IConsole {872da645-4a9b-1727-bee2-5585105b9eed}

[mpack]

You will not get that error with any VM, only with those that require VT-x. Given that you upgraded to Win10, the most likely reason for VT-x not being available is that you have Hyper-v running.

[Bazsl]

Thanks. Removing Hyper-V solved the problem.