1) The student actually might have not learned(played) the VOD.

2) Check the student's learning environment.

This can happen when the student attempted to learn(play) by opening the window, but closed the VOD after a certain amount of time elapsed without actual playback.

The state in which playback does not occur(the state in which progress is not checked) is as follows.

• When the network connection is not smooth
• When the device such as PC or laptop is in standby mode

3) Period Change Issue: Pre-period Learning → changing the start date and time earlier than the learning date and time.

Please check 'Pre-period Learning → changing the start date and time earlier than the learning date and time' in 'FAQ: Attendance(Progress Check) Period Change Issue' document.

4) Period Change Issue: Post-Period Learning → changing the end date and time later than the learning date and time.

Please check 'Post-Period Learning → changing the end date and time after the learning date and time' in 'FAQ: Attendance(Progress Check) Period Change Issue' document.

EX.