For anyone who might be encountering the same problem as me, the answer is to make sure all references are assigned correctly. Both forward and back. Also, I was initially wondering why a particular foreign key is causing problems while others are not. It turns out this particular foreign key is NOT NULLABLE while the others are so it didn't cause a problem. Initially, I was not setting the back references, I only set the references sufficient to perform cascade persist. Example, in the case above, I linked D to B so that when B is saved, D will also be saved. BUT, I did not link D to C so JPA had no idea that D is dependent on both B and C. Also, I removed the reference from C to D because in my case I didn't really need the relationship to be bidirectional.