How To Downgrade YACL Safely

When Downgrading Makes Sense

The clearest case is a dependent mod that supports only an older library range. The mod page states the requirement, and matching it is not optional if you want that mod in the setup.

A second case is a brand new build that conflicts with something specific in your pack. Rolling back one version while the projects sort it out keeps you playing instead of waiting, as the YACL updates guide discusses for update timing generally.

Key points:

• A dependent mod requires an older range
• A new build conflicts with your specific pack
• You are freezing a finished setup for a long world

Pick The Build By Requirement, Not By Date

Downgrade to the newest build that satisfies every dependent mod, not to an arbitrary old release. Check each mod page requirement and let the strictest one set the target version.

The build must still match your Minecraft version and loader exactly. An older library for a different game release is not a downgrade; it is a mismatch, and the game will treat it as one.

Back Up Before You Roll Back

Settings files written by a newer build can confuse an older one in rare cases, so copy the config folder before swapping files. The backup turns a failed downgrade into a restore instead of a retune.

Use the routine from the settings backup guide: dated folder, version note, and a copy kept away from the instance you are changing.

Swap The File And Test Properly

Remove the current library file from the mods folder, keeping it somewhere labelled, and place the older build in its place. Never leave both copies in the folder, because the loader will not reliably choose the one you want.

Test on a spare world or a copy first. Open the menus of every dependent mod, change one setting in each, and restart once to confirm saving still works before returning to your main world.

Knowing When To Upgrade Again

A downgrade is a position, not a life sentence. When the lagging mod updates or the conflicting build is fixed, return to the current library release so security and compatibility fixes reach your setup.

Keep a note of why you downgraded and which versions you pinned. Future you, reading a crash log months later, will be grateful for the explanation.

Document The Pin

Write the pin down where future sessions will see it: a text file in the instance folder naming the library version, the mod that required it, and the date. Launchers get reinstalled and memories fade, but a note in the folder survives both.

When you finally upgrade, update the note instead of deleting it. Yet Another Config version history for your own setup becomes a timeline that explains every future crash report in half the time.