FCPX 10.1 a/v output greyed out using AJA-T_Tap

Tried using fcpx 10.1 with they AJA T-Tap for the first time outputting with thunderbolt out of t-tap and SDI into Teranex but cannot get any video out when playing video out - the A/V Output in the fcpx window menu is greyed out. Tried messing about for a few hours and made sure latest AJA drivers are installed but no luck. The HDMI default output works sending the test signal to both the HDMI input on a TV and to the Teranex but cannot get video out. Anyone any ideas?

You did set the AV output preferences?

Could not do it because it states no options - it does not see the T-Tap although the t-tap is outputting the test pattern to both HDMI and Teranex.

Contact AJA and see if there are new drivers for this.

I did upload the latest driver on their site but will now ask them specifically on this issue.
Thank you.

Phoned Aja on Skype ( Iam in the UK) and they answered without delay but they are running fcpx 10.08 and so are now investigating why fcpx 10.1 does not see the T-Tap. I get the test signal on both HDMI and the Teranex so the T-Tap itself is working. It just that there just no output from fcpx because fcpx no longer detects the T-tap as an output option.

Well all the tricks from Aja did not work.
Then, although it did not make sense, I swopped the leads around so that the thunderbolt disc drive that contained the video reading into FCPX and the thunderbolt leading to the T-Tap changed over thunderbolt ports from the Macbook pro and bingo - all worked!!! I have no idea why.

Happy you got it worked out. The T-Tap is fantastic for the price- I run it's output via TB behind a string of two Pegasus r4s to my color correction monitor from my MBP retina. Thunderbolt is great, but can be finicky, especially as the peripherals start piling up - switching up ports should always be at the top of the list of things to try. Sometimes I get a weird "split screen" on output, but normally, I can just unplug the T-Tap and plug it back in with FCPX still open, re-select AV output (10.1.1 w 10/1/12 AJA Firmware) and walla, things are back online. Awesome times we live in.

Happy Editing,
Dusty