What I take from the error, is that the upgrade to Windows 10 messed up some files the VMware was using. It will be a little difficult to fix that, better uninstall VMware and all it's files, re-download VMware Workstation and the appliance and re-install them.
You can re-download the VMware Workstation just by signing in with your email you registered (your email on edX most possibly) and just write down your key from the previous order. You don't have to order a new one.
More information here: https://manual.cs50.net/appliance/2014/workstation/
The VMware Software Center is set up like a store. On the "store front" page, click on VMware Workstation 11. If you see both a free and a non-free offering of the product, choose the free one. In the drop-down menu labeled Choose a platform, make sure that Windows is selected. Click the Add to Cart button, then proceed through the check-out process until you reach a screen with a Start Download button. After a momentary delay, your unique product key should appear in red on that screen. Copy that key into a place where you keep software serial numbers and license keys. You’ll need it to install Workstation 11 now and to reinstall it later if the need arises.
Click the Start Download button to download the installer for Workstation 11.
If you copied that key somewhere you can use it to reinstall the appliance.
If not, go here
https://harvard-cs50x.onthehub.com/WebStore/Account/YourAccount.aspx
sign-in with your edX account (it's under the Single Sign-On option on the left), and click the View Details button under your purchace. You should see your key for VMware Workstation with red letters.
And next time make sure to follow the instructions ;).
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