can't activate video plugin

Hi
I bought Cross DJ on the Mac App Store and used it on a mac book air with no problem mixing songs and videos with no problems but because of iTunes 12 and yosemite I can't use the mac book air anymore...
So I got a mac book with 10.6.8 on it but the video does not work on it... Why that ? No way to find on your web site and on your difficult forum the requirement for the video plugin...
Thanks for answering
Also I already post on this forum and did not get notified of any answer or comment...
erick@hortolan.com
email used to buy at the Apple store : erick.hortolan@wanadoo.fr
I bought Cross DJ on the Mac App Store and used it on a mac book air with no problem mixing songs and videos with no problems but because of iTunes 12 and yosemite I can't use the mac book air anymore...

So I got a mac book with 10.6.8 on it but the video does not work on it... Why that ? No way to find on your web site and on your difficult forum the requirement for the video plugin...
Thanks for answering
Also I already post on this forum and did not get notified of any answer or comment...
erick@hortolan.com
email used to buy at the Apple store : erick.hortolan@wanadoo.fr