An attempt to start any virtual machine results in
Failed to open a session for the virtual machine Windows10x64.
The virtual machine 'Windows10x64' has terminated unexpectedly during startup with exit code 1 (0x1). More details may be available in 'F:\VirtualBox\Machines\Windows10x64\Logs\VBoxHardening.log'.
Result Code: E_FAIL (0x80004005)
Component: MachineWrap
Interface: IMachine {85632c68-b5bb-4316-a900-5eb28d3413df}
I uninstalled antivirus and tried running virtualbox as administrator; also uninstalled and reinstalled virtualbox. Didn't help. vboxhardening.log is attached, and it looks like ends with
supR3HardenedMainGetTrustedMain: LoadLibrary "C:\Program Files\Oracle\VirtualBox/VirtualBoxVM.dll" failed, rc=1790
VirtualBoxVM.dl is present in the directory, and according to procmon, is found and loads successfully.