Rosetta and macOS 27: why games stop launching after the update
Updated 29 September 2026 · Uncork version 0.16.2
Short version: if Windows games on your Mac stopped launching after the update to macOS 27, install Rosetta 2 again. The update does not bring it back, and the compatibility layer these games run on sits on top of Rosetta. The Terminal command is in the section below. Apple says the full Rosetta will shrink in macOS 28, and that is the big question for the future of every app of this kind, Uncork included.
What happened
macOS 27 “Golden Gate” came out on 14 September 2026 and runs only on Macs with Apple Silicon. According to Apple's documentation for the 27.0 release, Rosetta has to be installed again after the update: it does not return by itself. Apps that run Windows games on a Mac execute Windows programs through Rosetta, so without it they do not start. Heroic Games Launcher's tracker describes the error spawn Unknown system error -86 when Rosetta is missing (issue #5774, July 2026, macOS 27 beta), and the Porting Kit authors wrote on 20 September that after the update new installs in it fail until Rosetta is restored (their note).
How to fix it
Open Terminal and run:
/usr/sbin/softwareupdate --install-rosetta --agree-to-licenseThis is Apple's standard command. If you use Uncork, without Rosetta the app shows a banner with an “Install Rosetta” button that runs the same command; if the button does not work, use Terminal. We have not yet tried this button live on macOS 27. Your games and bottles stay where they are.
What happens in macOS 28
According to Apple, macOS 27 is the last version with the full Rosetta. In macOS 28, Rosetta will remain only for certain older games that depend on Intel-based frameworks (Apple's support page, MacRumors' summary). What exactly will be in that part, and whether it will run Steam and a compatibility layer, is unknown; in our assessment, Steam and such layers do not look like “older games”.
A path without Rosetta so far exists only as a test: an ARM64 build of the compatibility layer runs Windows programs another way. A preview of such a build came out on 31 July 2026, but it has no D3DMetal, the Apple graphics library that Windows games on a Mac rely on today.
What this means for Uncork
Uncork runs on top of Rosetta today, like other apps of this class, so this is the project's main risk for the coming year. We do not promise everything will work on macOS 28: it depends on what stays in the system and on whether D3DMetal appears for ARM64. For now, on macOS 27 the app shows a banner with an install button when Rosetta is missing.
Read next
- Uncork: frequently asked questions — price, safety, first launch, supported Macs and games
- How to play Windows games on an Apple Silicon Mac: every method — every way to play Windows games on Apple Silicon, with price and limits
- Apps for Windows games on a Mac, compared — price, licence, stores and notarization of nine apps as of 29 September 2026