This could be that the Assignment is Exempt, Incomplete, Missing, Late, or that there is a Comment Entered for that Assignment. This can also signify that there is a Absence while this assignment was due. If exempt changing the grade no matter how good or bad of a grade will not affect the Cum Grade as the Assignment does not count.
Tip: When you hover over the Red triangle you will see what status the Assignment was given.

To mark a Assignment as Exempt, Incomplete, Missing, Late, or that there is a Comment navigate to:
  1. The Gradebook for the Course in question
  2. In the Assignment Column hover on the box that corresponds to the Student you are trying to add the Status to
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     3. Click the red triangle in the top right corner of that box
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     4. Click Exempt, Incomplete, Missing, Late, or enter a Comment 
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