If while running Servo Tuner the data capture gets stuck at a percentage less than 100% so that it never finishes, the following may be the problem:
This problem was seen with Contoller tuner and it would get stuck at 7%. The reason was found to be that both Controller tuner and Drive tuner were on, so both were "connected" via RS232. The Motion Architect terminal window was also open and connected. When these two additional terminal connections were closed, Controller tuner could successfully capture data.