AFAIK, an AooB issue has nothing to do with the OBJ file.The issue is in your BP. Can you show us the BP? Specifically the array you are using.
AooB means that you are trying to access an index that is larger than the array size.
As you said, the OBJ file imported fine. Try dropping the imported mesh into the scene as a static object (no BP). That too should work fine.