I get that message a lot when I am out hunting...
It started after the 13.0 patch and it seems simmilar to the "Take it Easy" message.
It occurs when I fight in teams and have 4-5 MOB's attacking at once and I press the "Q" to attack.. it works fine, the mob dies, THEN I get 7-8 messages on my screen saying "Starting attack failed" I have not done anything after I first pressed "Q" to attack the first time... If I select a new target and press "Q" again, it usually works after I see the message a couple of times and my char starts to attack. I am a lvl 30 MA on Rubi-Ka 2.
Has anyone else experienced this, or perhaps know what causes it?