This has been happening more often lately and is a bit annoying. I'm not sure if any other players have experienced this problem, but during some battles when I select a mystery skill to use, my chakra will be taken however instead of preforming the action I will get a message on screen saying "System Error" after which the opposing team will take two turns worth of attacks on me. My chakra will then refill to 40 points, still not having complete the skill but the skill will still go into cool down.
At first I thought I just wasn't seeing the skill, but no damage is caused to the opposing team. So far this has only happened in instances and exam, never in a player vs. player setting.