Unfortunately, there is a new requirement for 2017 that requires a Federal EIN in order to claim the American Opportunity Credit. Codes "NC" and "00000" will not be accepted.
Without this number, you will not be able to claim the AOC but could still be eligible for other educational benefits such as the Lifetime Learning Credit.
If you have more questions about this, ask in the comment below.
Info on the Lifetime Learning Credit:
[Edited 03.24.19|11:32am PST]