Blank screen in yosemite

[Sean]

I've got a displaylink usb 3 to hdmi dvi and gigabit adapter that i'm trying to use with mid 2013 macbook air and yosemite. Adapter is not recognized by system when connected to powered usb 3 hub. Adapter is recognized by system when connected directly to macbook air usb port. When connected to macbook air usb port, monitor connected to the dvi port on the adapter appears to be recognized by the system and shows up in system preferences but monitor has a blank screen. Monitor appears to be getting a signal however. Gigabit ethernet works fine with this config but not when the adapter is connected to a powered usb 3.0 hub. I'm using driver version 2.5. Please advise on a possble fix. Thanks