This can occur for two reasons. Go to onBoard > Settings > Contracts Forms > Select Edit by the form in question.
Then check the following
1) Make sure that there is a fee schedule block in one of the sections. If there is no fee schedule block, add one with the appropriate tuition amounts and grade levels.
2) Check the student's grade level. Make sure that the student's grade level is one that is listed in the fee schedule and that the grade level has a tuition amount defined.