We have 4 macs that have Plugable USB 2.0 DisplayLinks connected to them. All for have lost the signals to projectors/monitors. They do not show up in the “Systems Preferences” like before and “detect displays” does nothing. I’ve tried uninstalling and reinstalling on all macs but can not get a signal. Both the Software (The latest available on the site) and hardware shows up in the “Systems information.” The only thing I can think thats changed is when we upgraded from 10.8.3 to 10.8.4.