virtualbox.org

I have two virtual machines for school work and I have worked a lot in them. From all of a sudden once when I wanted to start either of the virtual machines I get this error:
"Failed to open a session for the virtual machine (Callee RC: RPC_E_SERVEFAULT (0x80010105))"
And If I close the error window I get the windows saying: "Creating process for virtual machine xy (GUI/QT)... (1/2) and it's stuck on 0% forever.

The virtual machines are: Windows Server 2008 and Windows 7 but they worked flawlessly before.

I haven't made any changes on them or my computer or on anything all I did was once I unplugged every cable from the back ports of my PC but didn't touch anything inside let alone the hard drives or their cables. I really don't want to just reinstall the virtual machines because I have done a lot of work on them (including RAID so I have many drives) and I simply don't have the time to re-do everything again, so a fix would be much appreciated. Or if I have to re-install or re-do anything can I just export or save my drives so I don't have to re-do anything in the virtual machines?

Edit: I added the log file but I had to put it into 2 files because it was bigger than 128 kb

You don't mention your host OS, but if it's Windows 10, please right-click the VM in the main Virtualbox window's VM list, choose Show Log.

Search the far left tab's log for this text:

Attempting fall back to NEM

If you find it, Hyper-V is enabled and needs to be disabled. See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

If you don't find that text, save the far left tab's log, zip the log file, and post the zip file, using the forum's Upload Attachment tab. If you feel compelled to edit the log to hide some supposedly personal information, let us know you did so. Unreported edited logs will have to be rejected for lack of trust in the information.