Several sources (including an official manual posted here by the forum member Raevsky) state that in theory the available visa number may cease to exist, especially closer to the end of fiscal year. Such situation may happen, in my understanding, when a person files his I-485 not immediately upon his number became current, but some time later, say, half a year. My question is, do we have any real life examples of such visa shortage, and as a result, adjustment refusal?