It may be necessary to calibrate the Touch Screen.
Go to SYSTEM SETTINGS in the HOME Menu of the Nintendo 3DS system, select OTHER SETTINGS and then TOUCH SCREEN. Alternatively you can switch off the Nintendo 3DS system, and then switch it back on holding down the L, R and X buttons. This will directly open the calibration screen.
Use the stylus to touch the calibration points shown on the Touch Screen exactly in the centre. The calibration point is first in the top left corner, then, when it has been touched it moves to the bottom right corner, and then, when touched it moves to the centre of the screen, where it has to be touched one last time.
If calibration was successful, a confirmation is shown and new calibration points are shown in all four corners. Please touch all of the calibration points to check the result. Complete the calibration by selecting OK. Select RETRY to repeat the calibration.
If the calibration was not successful, the calibration point goes back to the top left corner and the calibration process has to be repeated from the start.