Match the warning to the branch you actually use
Branch names and update compatibility can change. Confirm whether Steam is on the standard, legacy or alternative branch and read the current publisher announcement before loading a valuable modded world.
| Branch/setup | Before launch | Scope note |
|---|---|---|
| Legacy/alternative branch with mods | Review the linked Unknown Worlds update notice; disable/remove mods as instructed for that update | Historical notice is not a universal mod rule |
| Standard branch, no mods | Read the current patch notes and preserve a backup | Do not assume the legacy-branch warning applies |
| Unsure which branch | Check Steam Properties > Betas and the installed version | Do not load the only copy to discover compatibility |
| Console | Use console-specific patch/support information | Steam branch instructions do not apply |
References: Unknown Worlds: Below Zero update and legacy-branch save warning
Protect the world before testing compatibility
A mod conflict can change the save when it loads. Keep an untouched copy outside the game directory so you can return to the prior state; avoid alternating branches on the same save.
- Record the platform, Steam branch, game build and enabled mod list.
- Quit the game and copy the complete SavedGames folder to a separate backup.
- Read the publisher's announcement matching the installed update date and branch.
- Disable/remove only the mods named by the applicable notice, keeping a note of what changed.
- Start the updated branch with a copied test world if available; do not overwrite the only original save.
- If the world errors or assets are missing, quit without saving and consult the current Unknown Worlds support page or a matching community report.
- Restore the original mod/branch setup only after confirming which versions are compatible.
References: Unknown Worlds: Below Zero update and legacy-branch save warning · Unknown Worlds: Steam Cloud disabled for Below Zero saves · Subnautica: Below Zero Steam Discussions
Before you play
- Steam branch and build recorded.
- Applicable publisher update notice identified.
- Full save folder backed up before loading.
- Legacy-branch advice not generalized to all users.
- No save overwritten during test.
Frequently asked questions
Should every Below Zero player remove mods after each update?
No. The cited warning is specific to modded legacy/alternative branches and a particular publisher notice.
Can I test on the only copy of my world?
Back it up first; the guide recommends a copied test world where possible.
Can this checklist detect mod compatibility?
No. It organizes a safe preflight but cannot inspect mods or predict a save result.
Sources & revision notes
Editorial revision: November 7, 2026; not a gameplay test date. The reference notes identify source limits and version differences.
- Unknown Worlds: Below Zero update and legacy-branch save warning (Official)
Publisher announcements warn players using mods on legacy/alternative branches to remove or disable them before launching after the cited update. The page is historical; check the active branch's current notice and back up first.
- Unknown Worlds: Steam Cloud disabled for Below Zero saves (Official)
Unknown Worlds announced Steam Cloud was disabled after reliability concerns and recommended manual transfer for Steam saves. This describes the PC Steam build at that announcement; verify current platform behavior before transferring.
- Subnautica: Below Zero Steam Discussions (Community)
Player-generated PC/Steam discussion. Save paths and cloud behavior vary by storefront, OS and platform; compare only reports with matching builds and do not follow destructive file advice without a backup.
November 7, 2026: first publication, bounded an Unknown Worlds legacy-branch update warning to its stated platform and branch scope. No save was loaded.
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