E_FAIL{0X80004005} error while starting Ubuntu in oracle virtual box

I am unable to start Ubuntu in oracle virtual box installed in windows 7 OS.I have imported .ova file.

this is the error message shown:

I had the same issue, after Windows updated itself.

On the virtualbox.org forums, they provide a few steps: https://forums.virtualbox.org/viewtopic.php?f=25&t=82106

However, that didnt help.

What did help, was updating VirtualBox from 5.1.22 to 5.2.6. My hypothesis here was that Windows had updated some dlls so I need to update VirtualBox so that its compatible with the new dlls.