Multimc Hackphoenix |link|

From surviving documentation and forum posts (circa 2019–2022), typical claims include:

The term "Hackphoenix" does not appear in official mod repositories (CurseForge, Modrinth). This strongly suggests it is one of three things: Multimc Hackphoenix

"Invalid signature file digest for Manifest main" test new mods

"Class net/minecraft/client/Minecraft not found" Multimc Hackphoenix

With MultiMC, players can easily create and manage multiple instances of Minecraft, each with its own set of mods, texture packs, and configurations. This means that players can switch between different modpacks, test new mods, or play with friends using different versions of the game.