Try this Microsoft KB article: Error message when you open the properties of a network connection: "An unexpected error occurred" and if the KB article don't solve your problem, since the problem is about some network adapter registry damaged, I recommend you do the following:
1. shutdown the VM and remove all the virtual network adapter;
2. open a command prompt and type: set devmgr_show_nonpresent_devices=1 and then start devmgmt.msc
3. on Device Management click View menu and then Show Hidden Devices;
4. search for the ghost network adapters, select the ghost network adapter, right click and Uninstall;
5. add the new network adapter and set the IP address again.