Installed the new macOS 27 beta and noticed your live Lock Screen or Screen Saver suddenly shows Apple's defaults instead of your video? You're not alone. The beta changed system wallpaper behavior under the hood, and the Lock Screen features of most third-party wallpaper apps stopped working overnight.
What changed in macOS 27
Apple regularly reworks system internals between major releases, and the macOS 27 beta is no exception. Lock Screen and Screen Saver wallpapers that worked perfectly on macOS 26 (Tahoe) silently stopped playing, no error, no warning. Apps built only for the macOS 26 behavior simply fail: the video never appears.
MacWall: the first app that works on macOS 27
MacWall shipped dedicated macOS 27 beta support ahead of everyone else. The result: live Lock Screen and Screen Saver video that keeps working natively on macOS 27: while competitor apps wait for rewrites. Switching back and forth is always safe, and your original system wallpaper is never lost.
How to get live Lock Screen wallpaper on macOS 27 beta
- Download MacWall from macwall.app/download.
- Pick any wallpaper from the catalog or import your own MP4/MOV.
- Enable "Use Lock Screen & Screen Saver" (MacWall Pro).
- Lock your screen, your video plays natively, even on the 27 beta.
If your system wallpaper got stuck
Switched between apps and now the Lock Screen shows the wrong thing? MacWall includes a one-click repair tool in Settings that cleanly restores Apple's default Lock Screen and Screen Saver. No Terminal, no reinstall.