Learning Activities - Red 'X'

Summary

What does a red 'x' mean next to a Learning activity?

Content

I know what the empty circle, half circle and green check mark mean, but what does the red 'x' mean next to a learning activity?

The activity in question is a SCORM file with a knowledge check at the end. The user who sent in this screenshot states that he completed and passed the knowledge check, but he is not marked as complete on the course and is seeing this red 'x' next to the SCORM activity.

Thanks,
Matt