Before you update to this new version, you should mine all Vintage blocks and discard any related items as well as all other Vintage items; otherwise, you could destroy your world..

Changelog

1.21.1 v1.6.3

• Ported the complete Forge 1.20.1 mod to NeoForge 1.21.1 and Create 6.
• Preserved the existing blocks, items, models, textures, recipes, Ponder scenes and machine functionality.
• Ported all Vintage KubeJS recipe schemas to KubeJS 1.21.1.
• Restored HeatJS custom heat levels for pressurizing and vacuumizing recipes.
• Restored Hammering modifyResult() with Minecraft 1.21 data-component support.
• Fixed Vacuum Chamber mode switching with the Create wrench.
• Fixed the Helve Hammer not consuming its recipe ingredients.
• Fixed black rendering on the moving Helve Hammer and Laser models.
• Fixed Curving Press head durability and consumption of non-damageable custom heads.
• Fixed recipe codecs, tags, creative-tab registration and client startup compatibility.
• Fixed dropped-item insertion and output preservation on the Vibrating Table.
• Allowed item and fluid input/output access while the Centrifuge is running.
• Fixed storage-block unpacking recipes on the Vibrating Table and their JEI category.

We had changed the KubeJS Syntaxes as well, please look at our wiki for it.