So I was recently working with some really old Virtual machines in a development environment that came across from another organisation. One particular virtual machine gave me an error message when I tried to start it up “An error occurred while attempting to start the selected virtual machine(s)… The security ID structure is invalid (0x80070539)”. When this happens, Hyper-V basically doesn’t have permission to start the selected virtual machines under the user. A quick administrative PowerShell cmdlet will grant me or a user permission and allow us to start the VM up;
Grant-VMConnectAccess -VMName "Name of VM not starting" -UserName "DOMAIN\Username of current user"
Changing -VMName to match the virtual machine giving you the error and a DOMAIN\Username of the user you are now logged on as.
Once you issue this command the virtual machine will start without any issues.