Minecraft 1.21.1 is a current Aquamirae target, but “1.21.1” alone is not enough information to install correctly. You also need the matching loader branch, its dependencies and a safe plan for world generation.
Current 1.21.1 release context
As checked on September 22, 2026, Aquamirae 7.2.10 is listed for the NeoForge 1.21.1 line and for the separate Fabric / Quilt 1.21.1 edition. Treat that as dated context: the important rule is still to match Minecraft, loader, Aquamirae and every required dependency as one compatible set.
Choose the correct 1.21.1 loader
Current project listings include 1.21.1 builds for NeoForge and a separate Fabric edition that also lists Quilt support. These are not interchangeable files. Decide which loader your profile or modpack uses before you download anything.
Prepare the world before adding Aquamirae
Aquamirae adds world-generation content. Back up your save before changing the mod list, and expect the Ice Maze and related structures to appear in newly generated terrain rather than overwriting already generated chunks.
Installation checklist
Keep Minecraft, the loader, Aquamirae and required dependencies on compatible versions. If the game closes during loading, retest with only the loader, Aquamirae and its required dependencies before adding the rest of the modpack.
What to test after launch
Create or copy a test world, confirm the game reaches the main menu, verify no missing-dependency message appears, and then travel into fresh frozen-ocean terrain. This separates launch problems from world-generation questions.