I'm trying to add "14th level School of Necromancy" as a prerequisite to my homebrew feat. Adding Wizard class seems to work as intended, but the subclass doesn't. On my list of Unavailable feats under "Manage Feats" it gives the reason "Missing: School of Necromancy" that it is unavailable, even though the character has this trait. I attempted to move over to a different subclass and back, and that didn't fix it. Of note, there are many things that are not subclasses or classes (for instance there are many races and subraces) under the "Class" menu of prerequisites, so I'm not sure if the developer perhaps meant for the program to search for a Class called "School of Necromancy" rather than a subclass, and the program obviously isn't finding one. 

https://www.dndbeyond.com/homebrew/creations/create-feat/1507160-queen-of-the-damned/edit

This is the feat

Are you using the official School of Necromancy, or a homebrewed version?

The official version. Thank you for your helpful question

Okay. Did you attach any other prerequisites to that feat?

I attempted to make it level 14 in the School of Necromancy.  The only prerequisites now are "Class: School of Necromancy + Wizard: 14".  It wasn't working when I did Class: School of Necromancy: 14" nor just "Class: School of Necromancy".  However "Class: Wizard" does work.