I guess we'll need to update our instructions to say to upload a screenshot only if it contains any actual information
My suggestion, try rebooting the host (possibly powering off and on to be really sure). See if that will allow VirtualBox to allow hardware virtualization. Your CPU can do it, and it should be available.
As a side note, if downgrading to the previously working version didn't help, there must be something else causing trouble. Maybe upgrading VirtualBox had nothing to do with it.