I'm struggling to connect my MacBook Air from 2011 (running 10.11.2) to my Acer XB270HU G-Sync. My monitor carries a DisplayPort and has no other ports except USB. I've tried a passive (male) mini-DisplayPort to (female) DisplayPort adapter, in combination with a male to male DB cable. However my monitor remains black and does not detect any signal from my MacBook. I've also tried a mini-DP to DP cable and again with the same results. The 'Displays' menu in System Preferences shows no external monitors. I've been trying to make this work for quite some time now, searched all fora, but could not find a similar issue. What is the correct setup to connect my MacBook Air from 2011 to my DP Display?