virtualbox.org

Dear readers,

For the past years I've been using VirtualBox to create VM's to try out and learn any OS I found and used it to teach my students build a client network setup with Windows.
Out of nothing today none of my VM's worked anymore. I got a message saying a fatal error occured but no specific reason in the message.
The message is in Dutch so I didn't bother taking a screenshot but I added the log fils below in a zip file because the text file was too big to upload on the forums. I tried rebooting, reinstalling VirtualBox already 3 times but nothing changed. I lost all my VM's sadly but I hope you can help me out to fix the issue so I can continue using VirtualBox.

Thanks in advance!

I hardly even need to look at the log: your last Windows update enabled Hyper-v, or you enabled it yourself by choosing some component that needs it.

But, just for form's sake, here is the confirmation from the log.

00:00:06.736250 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:06.784881 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

And here is the relevant FAQ: HMR3Init: Attempting fall back to NEM (Hyper-V is active)