Your Mac screen saver stopped working after macOS Tahoe

On macOS 26 Tahoe, Apple's guide now tells you to open System Settings, click Wallpaper in the sidebar, then Screen Saver on the right: the pane is no longer a sidebar entry. Third-party savers are filed under Other, at the very bottom. If yours is truly dead, the cause is the shared legacy host, not your file — here are the checks, in order.

Updated 2026-09-10 · 8 min read

macOS 26 didn't break your screen saver — it moved the pane

Open Apple's guide Change Screen Saver settings on Mac in its macOS Tahoe 26 edition and the first instruction reads: “To change these settings, choose Apple menu > System Settings, click Wallpaper in the sidebar, then click Screen Saver on the right. (You may need to scroll down.)” The macOS 14 and 15 editions of the same page say: “choose Apple menu > System Settings, then click Screen Saver in the sidebar.” That diff, verifiable page against page, is the whole story for many people typing this query. The Screen Saver pane is no longer a sidebar entry; it became a sub-page of Wallpaper.

Beta testers described it in June 2025. The MacRumors thread opened on 9 June 2025 puts it plainly: “There's no longer a Screen Savers pane in System Settings. Instead, you go to Wallpaper. Within that, there is a ‘Screen Saver…’ button.” The window behind that button was reported as a modal dialog, “non moveable and non resizable”. The same month, a developer on Apple's forums noted that open x-apple.systempreferences:com.apple.ScreenSaver-Settings.extension, the command that used to jump to the pane, no longer worked for that reason. Beta-era observations, but they explain why an old shortcut or shell alias pointing at the former pane identifier now opens nothing.

So say it directly: a part of the “my screen saver stopped working” reports are really “I can't find it any more”. Nothing was uninstalled; the settings moved.

Your .saver is probably still installed — it's filed under “Other”, at the very bottom

The macOS 26 guide also says where third-party savers live now. Its description of the pane ends with a section called Other: “Click Photos or one of the screen savers. Click Random to shuffle through the screen savers. Click Options at the top of the window to set color, speed, and more, based on the screen saver you select.” It sits below Apple's aerials and built-in savers. The maintainers of Aerial, one of the most widely used third-party savers, add the detail Apple omits: “It appears at the very bottom, so scroll down and press See More to reveal it.” iScreensaver, an independent vendor, posted the same procedure on 10 June 2025: System Settings > Wallpaper > Screen Saver, scroll to “Other”, select the saver by hand.

If it is genuinely absent from “Other”, check where the file went. macOS reads third-party .saver bundles from ~/Library/Screen Savers for the current user and /Library/Screen Savers for every user on the Mac. Apple's own savers sit in /System/Library/Screen Savers, where nothing of yours belongs. Move the bundle to ~/Library/Screen Savers, quit and relaunch System Settings, then look under “Other” again. This is a cleanliness test for the install, not a fix for the host bugs below.

One more detail from the Aerial FAQ: since Sonoma, and still on Tahoe, picking a screen saver in System Settings applies it only to the display and the Space you are on at that moment. A saver that seems to have “reverted” on a second screen may never have been set there.

Why every third-party screen saver fails at the same time

Now the cases where the saver really is broken. Since macOS 10.15 Catalina, Apple builds its own screen savers, aerial views included, as app extensions: .appex bundles. The Aerial FAQ states the consequence: “the API has been private the entire time; Apple has never documented it publicly, which is why every other third-party screensaver still ships in the older .saver bundle format.” Third parties are left with the old .saver API and what the project's README calls the “terrible legacyScreenSaver.appex ‘compatibility layer’”.

That name is the key. It is a plug-in loaded in-process into one shared host, legacyScreenSaver.appex, together with every other saver on the Mac. Aerial's FAQ describes the opposite, the situation its extension build enjoys: it “runs in its own process and sandbox, not bundled inside Apple's shared legacy screensaver host alongside every other .saver you have installed.” Read that backwards and you have the answer to “why did all of them stop at once?” One host, one process, every third-party saver inside it: a single host bug takes them all down together.

Apple does not dispute the diagnosis. In August 2025, on a Developer Forums thread titled “Is there any future for screensavers on macOS?”, an Apple DTS engineer wrote: “Screen savers are fundamentally difficult to maintain because they use the old in-process plug-in model. It would be better if we updated the API to support the more sustainable app extension plug-in model.” On the requests to open that API to third parties, FB6363533 and FB19235887, the answer was that it “won't happen in macOS 26”. That is not a deprecation, and Apple has never written that .saver is finished; it is an admission that the model is old and hard to keep working.

The accumulation bug is the one the Aerial maintainer called the worst: “3rd party screen savers are no longer stopped and keep running all the time”, which is why the host keeps eating CPU after you sit back down. Then there is the black-screen state, described in September 2025: once something in the host gets “messed up”, macOS “will just refuse to try to launch the 3rd party screensaver (giving users a black screen). Only fix in those scenarios is to restart macOS.”

One honesty note. That accumulation bug was “introduced in Sonoma”, in the maintainer's words, and on 1 January 2026 MacRumors users report it on Tahoe 26.1 and on Sequoia 15.7.3 alike. Tahoe did not create the fault; it stacked an interface change on top of a regression from macOS 14. That is why it feels like everything broke the day you updated.

The checks, from the most likely cause to the rarest

The list below is ordered by how likely each cause is, not by a measured success rate; nobody has published one and this page will not invent it. The first two items cost nothing and settle the cases where nothing is broken. The third is a settings conflict. The next three deal with the shared host, and the last one with the file itself. Stop at the first that brings the saver back; if you reach the end, the problem sits in the host, and the next section covers that.

A word on the Activity Monitor step. Open Activity Monitor from Applications > Utilities, type legacyScreenSaver in the search field, select the row, click ⓘ, then Quit. Expect it to relaunch the next time a saver runs. Users on the January 2026 MacRumors thread summarise the situation without illusion: “either rebooting works (until it stops working again) or force quitting the legacyScreenSaver process in Activity Monitor sometimes helps.” On the Apple Community the same process has been reported at 100 % CPU, which is when quitting it stops being optional. The Terminal variant, killall legacyScreenSaver, does the same thing. A host that stacks instances also draws power, which makes what animated desktops cost in battery relevant to a saver you thought had stopped.

When the only fix is a version that is no longer a .saver

One third-party saver no longer goes through the legacy host, and it matters precisely because it is the exception. Since version 4, Aerial “is now distributed as an App Extension, bundled inside the Aerial.app”; it is no longer a .saver. The maintainer's summary: “no more random black screens, no more stacking screensaver instances on wake”. As of 29 August 2026 the stable release is 4.0.16 (published 25 August 2026, macOS 15 or later, Apple Silicon and Intel); a 4.1.0 beta of the same date requires macOS 26 or later and “does NOT work on Sequoia”. The last .saver build, 3.6.3, is frozen.

The caveat is in the same FAQ and it is not negotiable: “Aerial 4 is the first third-party screensaver to implement this via the private API. … The API is private and still undocumented by Apple.” It is one project building on an interface Apple never published: not a route open to every developer, and not an update an abandoned saver will ever receive. iScreensaver, the second vendor to speak publicly, wrote on 12 September 2025: “we do not recommend using macOS Tahoe 26.0 if you plan to use any third-party screensavers”; its own Tahoe support arrived with build 6.9.0.1378, then 6.9.1 on 16 September 2025. Two independent vendors, one diagnosis: the host, not a saver.

The practical rule: look on the saver's site for a release dated after September 2025 that mentions Tahoe. If the last update is from 2023 or earlier, there is nothing to repair on your side. The file has not changed; the host it runs in has. And as of 29 August 2026, macOS 27 “Golden Gate”, expected in September 2026 and Apple Silicon only, came with no announced screen saver API for third parties: a dated absence, not a forecast.

What doesn't break: a wallpaper drawn by an app, not by a system plug-in

Here is what this diagnosis implies for the other reason people install a screen saver: a desktop that moves. A live wallpaper drawn by an application runs inside that application's own process. It is not a .saver, it is not copied into ~/Library/Screen Savers, and legacyScreenSaver.appex never loads it. It sits outside the blast radius of a shared plug-in host, not because it is better engineered than your saver but because it is a different kind of thing.

Mac+ is built that way. Its scenes are rendered in real time on the GPU with Metal, at a resolution and frame rate you choose (30, 60 or 120 fps). Rendering pauses automatically when the display sleeps or when a full-screen window or app covers the desktop. Activation is per display and re-applied when you plug a monitor back in, which matters if the second-monitor bug above is the one biting you; live wallpaper on multiple monitors walks through that setup. Mac+ does not fix the fault. It removes the reason to depend on a screen saver to get a moving desktop.

The limit belongs in the same paragraph. Mac+ is not a screen saver: it does not start after your idle delay, it does not hide your desktop when you walk away, and it repairs none of the Feedback IDs listed above. Your screen saver will stay broken until Apple fixes the host or its author moves to another format. If a moving background was the real goal, free animated wallpapers for Mac and setting a video as your wallpaper cover what works on macOS 26. Mac+ runs on macOS 13 or later, Apple Silicon and Intel, free without an account; the paid tier is €1.99 a month or €9.99 once.

Check these seven things, in this order

1. Open Apple menu > System Settings, click Wallpaper in the sidebar, then Screen Saver on the right. The dedicated sidebar pane no longer exists on macOS 26; scroll down if the button is not visible.
2. In the Screen Saver window, scroll to the “Other” section at the very bottom and click “See More”. Third-party savers are filed there, after Apple's own.
3. Compare two delays that live in two different panes: “Start Screen Saver” (Wallpaper > Screen Saver) must be shorter than “Turn display off on battery / on power adapter when inactive” (Lock Screen). If the display switches off first, the saver never gets a chance to appear.
4. Open Activity Monitor, search for legacyScreenSaver, select the process, click ⓘ, then Quit. Instances stack up and keep running. Reopen System Settings afterwards and try the saver again.
5. Restart the Mac. It is the only known way out of the state where the screen goes black and macOS refuses to launch the third-party saver at all.
6. If the symptom is “it never starts on its own any more”, start up in safe mode once, then restart normally: system caches are cleared and rebuilt. Reported as the fix on Tahoe 26.3 on 2 March 2026.
7. Reinstall the .saver into ~/Library/Screen Savers and relaunch System Settings. If the author now ships an app plus extension instead of a .saver, install that version instead.

macOS 13 or later. Apple Silicon and Intel. Free tier, no account required — €1.99/month or €9.99 once for the paid tier.

Frequently asked questions

Keep reading

Sources

• Apple Support — Change Screen Saver settings on Mac (macOS Tahoe 26)
• Apple Developer Forums — macOS 26 Tahoe Screen Saver issues
• Apple Developer Forums — Is there any future for screensavers on macOS?
• Aerial — FAQ: What is an AppExtension screensaver?
• Apple Support — Change Lock Screen settings on Mac (macOS 26)

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