: In the modern launcher, players may default to the name "Player524," which can prevent joining multiplayer servers without third-party name-fixing tools. Minecraft Wiki A word of caution
You will find many sites offering “Minecraft Alpha 1.2.6 updated.jar” or “.exe” files. — most are malware. If you absolutely need a clean, unmodified Alpha 1.2.6 client jar, it’s available inside your .minecraft/versions/old_alpha a1.2.6/ after you install it via the official launcher. minecraft alpha 12 6 download updated
You can download and play this version through several reliable methods: Official Minecraft Launcher : In the modern launcher, players may default
Follow these steps to access this historical version using the official launcher: : : In the modern launcher