Project Zomboid Pre-Release Branch — Testing 42.22 Without Losing Your Save

On October 27, 2026 The Indie Stone renamed the Unstable branch to Pre-Release and shipped 42.22 onto it. Stable is still 42.21, and it stays that way until 42.22 has been tested for at least a week. This page is the operator's version: how to opt in, what you are signing up for, how to protect your saves, and how to get back to 42.21 if a mod or server breaks.

What actually changed

The stated reason for the rename is that "Unstable" had caused confusion among players, given its long history in Build 42. The new name describes what the branch actually is — a build in final vetting before it reaches Stable.

Urgent hotfixes are the stated exception: they may still go straight to Stable, bypassing Pre-Release entirely.

How to opt in to 42.22 (Steam)

1. Back up your saves first. Copy the Zomboid/Saves folder somewhere dated (see the file-location table in the error fixes guide if you are not sure where it lives).
2. Right-click Project Zomboid in your Steam library → Properties.
3. Open Game Versions & Betas.
4. Select Pre-Release from the branch dropdown.
5. Let Steam download the update, then launch and confirm the build version on the main menu before loading a save.

To go back: same menu → select None (the default branch), and Steam re-downloads the stable 42.21 build.

What you are signing up for

• Your save is not guaranteed to survive. The official wording: 42.21 saves "should not be affected," but pre-release saves are not guaranteed to work in the final release. Do not move a long-running single-player world onto Pre-Release without a copy.
• Mods break first. Java mods and third-party loaders sit on unsupported internal code and break without warning on any update — the studio said so explicitly in its Java mods policy. Lua mods are supported and loadstring/loadstream are enabled again since 42.21 (mods guide).
• Servers are all-or-nothing. A dedicated server on 42.22 needs every client on 42.22, and vice versa. Never upgrade a live server you cannot restore from a backup; clone the server directory and test there (dedicated server guide).
• Bugs belong on the official forum. The studio asks for reproducible reports on a fresh save with no mods — reports on Discord or elsewhere are likely to be missed.

What is in 42.22

The headline features are the ones players have requested since launch:

• Working ladders — climb with E, zombies cannot follow. Full mechanics: ladders and crowbars guide.
• Crowbars force openings — windows, wooden and metal doors, fence gates and garage doors, with Strength and Burglar modifiers, crowbar damage on repeated failures, and Muscle Strain.
• Pushing while encumbered — you can now shove with full hands, dropping the blocking item instead of being frozen.
• No sleeping with a Bad Smell — generator fumes and corpse stink now block sleep outright.
• Walk-and-do actions — ammo boxes, umbrellas, clothing rips, batteries, candles, propane bottles and cigarettes all work while moving.
• Multiplayer repairs — server-side PvP damage, the doppelganger/cloned-character fix, trailer physics and towing desync fixes, faster server backups, and a working "All Known On Start" option.
• Animal fixes — no more deaths on zone unload, rabbit kits finally nurse, chickens stop disappearing from full hutches.

The full consolidated list is on the Build 42 changes page; the raw notes are The Indie Stone's "42.22 Patch Notes" in the PZ Updates forum.

Should you switch?

Stay on Stable (42.21) if: you have a long-running save, you play on a server with other people, you rely on Java mods, or you just want to play rather than test.

Try Pre-Release (42.22) if: you are a modder or server admin getting ahead of the next patch, you are starting a throwaway test world, or you specifically want ladders and crowbar forcing now.

FAQ

Is 42.22 stable? No. As of October 30, 2026 it is a Pre-Release test build; stable remains 42.21.

When will 42.22 reach Stable? The studio's rule is at least one week on Pre-Release, longer if issues require another revision. No date has been announced.

Will opting in delete my 42.21 save? The official notes say existing 42.21 saves should not be affected — but loading a world on 42.22 writes it forward, and pre-release saves are not guaranteed to work in the final release. Back up first, every time.

Can I run a 42.22 server for friends on 42.21? No. Clients and servers must be on the same version; the game now warns about mismatches instead of hanging.

Did the Unstable branch disappear? Effectively yes — Pre-Release is its replacement, and going forward every new build is tested there before Stable.

Verified on 42.21 stable & 42.22 Pre-Release · Last checked 2026-10-30

Branch rename, opt-in path, release cadence (minimum one week before Stable), save-compatibility caveats and 42.22 feature list: official "Moving on Up: 42.22 Pre-Release" (The Indie Stone, October 27, 2026) and "42.22 Patch Notes" (PZ Updates, October 27, 2026). Stable status and 42.21 release date: "42.21 Stable Released" (September 28, 2026). Java mod support limits: "A Note on Java Mods and Modding" (October 21, 2026).