Subnautica 2 Update: September 3 Patch Fixes Power Plant Turbines

The first patch for the 1.2 "Among Friends" update of Subnautica 2 arrived on Steam on Tuesday, September 1, 2026, at 15:09 UTC, that is 17:09 in Paris — our own conversion, as the announcement gives no time zone. Unknown Worlds then updated it: a line dated Thursday, September 3, 2026 was added at the top of the post, above even the original "Hello everyone." It fixes a progress-blocking bug.

The text runs to a single sentence: "We've fixed an issue where in-progress Axum Powerplant Turbines disappeared or were no longer completable." Power plant turbines under construction were disappearing, or refusing to be completed. This is the step that unlocks the observatory, meaning the end of the narrative content for early access: an affected player could no longer progress.

Who pays what, after September 3

The second sentence of the addition is the one that can't be guessed: "Players affected will now see the Powerplant Turbine ghost again and be able to complete the building at no cost." The construction ghost reappears and the building is completed free of charge. Those who reach this step after the update will, however, pay the resources normally.

One caveat: the studio never states at any point what happens to resources already sunk into a build swallowed by the bug. The free completion applies to finishing the building, not to a retroactive refund. We detailed the recipe and logistics for this turbine in our guide from August 9, 2026; nothing in this patch changes it.

"Axum Powerplant," "Power Plant," "the power plant": three labels for one building

The building that the September 3 addition calls the "Axum Powerplant" has never carried that name in Unknown Worlds' other communications.

The alignment can be checked line by line: where the English 1.2 notes fix a spot under the map "near the east side of Power Plant," the French notes published the same day by the studio speak of "un trou à l'est de la centrale électrique" (a hole east of the power plant). Same patch, same position in the list.

As for Karakorum, the name we ourselves had used on August 9: it does not appear a single time in the thirty Steam announcements published by Unknown Worlds between April 21 and September 1, 2026, either in English or in French (checked on September 4, 2026). We are therefore not settling the matter between Karakorum and Axum. The only officially attested French label is "la centrale électrique" (the power plant), and that is the one we use.

Saves no longer roll back, and mods must be disabled

The line with the heaviest consequences doesn't concern the power plant: "Save files now track build number and branch, preventing incompatible saves from being loaded into older builds." Every save now carries its own build number and branch, and the game refuses to load it on an older version.

This is the hardening of a trap we described on August 13, when the studio opened its Experimental branch on Steam and Xbox: incompatibility was then an announced rule, it is now written into the file and enforced by the game itself. Two side fixes follow: the compatibility tooltip finally displays correctly, and a detailed error log has been added for write failures ("Platform write failed for save slot").

Watch out for what the studio doesn't say: the sentence only targets loading onto an older version. Nothing about the reverse direction, nothing about the fate of a save created before the fix, which therefore carries neither of these two markers.

Second instruction, in bold from the publisher: "please temporarily disable, remove, or uninstall" your mods before relaunching the game. They will not be updated for this fix and may cause crashes on startup. Finally, "this hotfix may take some time to roll out worldwide": not seeing the fix immediately is not another symptom.

The French localization fixed, and shifting terminology

Two entries in the patch explicitly concern localization: descriptions for the PDA and the databank were displaying without their translation, and the names of the two characters added by 1.2 to the selection screen, Jegna and Grace, were not appearing translated. The studio does not specify whether it's targeting the names themselves or the text accompanying them.

Ironic twist: this very patch isn't translated. Requested in French, the Steam announcement remains entirely in English. The labels below therefore come from the 1.1 and 1.2 notes, published in French by the studio, and not from an in-house translation.

One case is worth pointing out: the patch mentions "wall racks." Yet the 1.2 notes, fifteen days earlier, announced exactly the opposite — the portable item racks "now have the same name throughout the game," after having carried two competing names that the update removed. The publisher thus reuses, in its own patch, a designation it had just unified.

The rest of the patch, by category

Bases. Items stored on portable item racks are finally refunded through the "Refund Base" option. Outdoor furniture becomes movable again when playing as a client, the power transmitter radius no longer displays incorrectly, and sea currents no longer affect players sheltered inside a base. On the file size front, two cleanups: leftover data from the item spawning system, and construction ghosts that remained registered after the fact. The studio does not put a number on the gains.

Creatures. The Collector Leviathan's movement is improved in the lower parts of the canyon and its collision detection tightened; the tracker's detection radius is increased; breathing markers on hydrophore slugs no longer appear when the creature is in the inventory; certain exploits no longer allow escaping the grip of an aggressive creature.

Vehicles, multiplayer and miscellaneous. Players clinging to a Seatruck Pup or seated in a FORT chassis now reliably receive oxygen again; inventory sharing is blocked while traveling and dying mid-trade no longer breaks anything; the "push to talk" input for proximity voice chat is fixed. Also added: a lockup on the character selection screen, misaligned distant alignment guides, and the "Moonpool shrink mode" that wasn't checking collisions.

In practice

1. Your turbine had disappeared: restart the game and go back to the power plant. The ghost should be back, and completing it won't cost you anything.
2. You haven't reached that point yet: nothing changes, expect to pay the full bill.
3. You're playing with mods: disable them before launching the game.
4. You're on the Experimental branch: your save now carries its branch and build number, and it won't roll back.
5. You don't see the fix: the rollout is gradual, according to the studio.

This is a quality-of-life patch that was hiding an emergency: about thirty lines of polish, and in the middle of it two decisions with real stakes—a fix offered free of charge to those the bug had left stranded, and a save file that has become a prisoner of the version that created it.