Minecraft Alpha 1.2.6-01 is not a standard release of Minecraft. Official records indicate that Java Edition Alpha v1.2.6, released on December 3, 2010, was the final bug-fix update for the Alpha 1.2 "Halloween Update" cycle.
In Alpha 1.2.6_01, you had exactly 28 block types (excluding tools). That was it. minecraft alpha 1.2.6-01
Purpose: Primarily focused on fixing issues with the newly implemented multiplayer (SMP) and correcting specific block behaviors. Minecraft Alpha 1
According to these fictional tales from the Minecraft CreepyPasta Wiki, this version was "never meant to be released" and contains haunting anomalies: Purpose: Primarily focused on fixing issues with the
The Ghost in the Code: An Analysis of Minecraft Alpha 1.2.6-01