Entity Framework Pitfalls: Null Navigation Properties
What if, after you load an entity, you have a reference property for another entity that is null yet you are sure that it points to a valid record? This will likely be because of one of two things:
Lazy loading is globally disabled (the LazyLoadingEnabled or ProxyCreationEnabled are set to false);
The containing entity does not qualify for lazy loading (it is sealed or the reference property is not virtual).
Anyway, you can always tell by code if the property is still unloaded and force it to load:
1: if (ctx.Entry(entity).Reference(x => x.MyReference).IsLoaded == false)
3: ctx.Entry(entity).Reference(x => x.MyReference).Load();