Verify the code signature of the extracted .app :
No. A full functional DMG containing the installer app is ~12.7 GB . If yours is 10GB, it is missing the SharedSupport folder and will fail during installation. Redownload from a verified source. macos big sur 1121 installer dmg
20D74 (Initial release) / 20D75 (Revised release) Verify the code signature of the extracted
Unlike the standard Software Update pane in System Preferences, which downloads the installer directly to the Applications folder, a file provides a portable, reusable copy of the full OS installer. a file provides a portable
macOS Big Sur 11.2.1 is a maintenance update to macOS Big Sur, which was initially released in June 2020. This update addresses several issues, including: