Unable to open existing VM's after updating from 5.0.40 to 5.1.26

[doughbaby]

I have been trying to update for months now. My install goes fine, but my existing VM's will not start after updating to 5.1.26. I have the exact same problem on 2 different machines with same hosts and guests, but at different physical locations. Host is Windows 7 ultimate 64bit. Guests are Windows 7 ultimate 64bit, and Windows 10 64bit. If I roll back to previous version all is fine. I assume I could install new guests on new version, have not tried, but I have a slow connection and the download time would be brutal. The error message i receive is below. Thanks in advance, any help on this subject would be greatly appreciated.

Failed to open a session for the virtual machine Win7-64bit.
The virtual machine 'Win7-64bit' has terminated unexpectedly during startup with exit code 1 (0x1). More details may be available in 'C:\Users\doughbaby\VirtualBox VMs\Win7-64bit\Logs\VBoxHardening.log'.
Result Code: E_FAIL (0x80004005)
Component: MachineWrap
Interface: IMachine {b2547866-a0a1-4391-8b86-6952d82efaa0}

[mpack]

FAQ: Diagnosing VirtualBox Hardening Issues.

[doughbaby]

I sure appreciate your time and help mpack. Running the system file checker with scan now fixed my issue. Been messing with this for months, can't thank you enough!