Hello djem38
First, please upgrade to version 10.2.2.
When you go back to the last year the student was enrolled, enter the Students > Student Info program.
Then, change the Rolling / Retention Options to either "Retain", "Next Grade at current school" or whatever is appropriate.
Save, now you should have an "Enroll student for next school year" link appearing.
You will find more details at the end of the Rollover Guide PDF.
Please let me know if this works for you!