- Make a NeoForge 21.1.244 profile for Minecraft 1.21.1 in any launcher (Modrinth app, CurseForge app, Prism Launcher) and give it at least 8 GB of memory.
- Download AutoModpack 5.0.0-rc.4 (the build the server runs, from Modrinth) and put the jar in that profile's
modsfolder. - Add the server as
maxxmods.experiment.al#amp1=5d72edada9be1f7ccb95d43bc8c6c4436a90e39731dc60285e31ae9733643e17and join. AutoModpack downloads the mods, closes the game once, and you start it again.
If you added maxxmods.experiment.al without the #amp1= part, AutoModpack shows the server's certificate fingerprint on the first join. It must read 5d72edada9be1f7ccb95d43bc8c6c4436a90e39731dc60285e31ae9733643e17; accept it once, and nothing else.
If automodpack-mc1.21.1-neoforge-4.0.6.jar is still in mods, delete it first. Two AutoModpack jars stop the game from starting.