Hi guys, I've got a mid-2012 Macbook Pro 15 inch, non-retina. Intel i7, Nvidia GT 650m, 8gb RAM, OS X 10.10. I've been using a 27 inch Acer monitor with a mini DisplayPort to HDMI adapter for several months now. After updating to Yosemite on Thursday, it was still working fine. Yesterday, however, the computer no longer recognizes the monitor. The screen flickers when I plug it in, but nothing displays on the larger screen. I know the monitor works, it displays my Xbox just fine. I've tried different HDMI cables to no avail. The only hardware left to test is the adapter, but I want to rule out software before I buy a new one to test it. Any suggestions? Thanks!