You are not alone. Apple officially discontinued Lion (10.7) years ago, and the original download links from the Mac App Store are long dead. The remaining copies floating around the internet are often incomplete, improperly patched, or simply broken.
cd ~/Downloads dmg extract MacOSXLion1072.dmg -o LionPayload (If dmg command not found, install dmg via Homebrew: brew install dmg2img )
shasum /path/to/your/InstallOSXMountainLion.dmg (Replace the path with your actual file location, renaming to Lion). mac os x lion 1072 dmg file fixed
8 GB USB flash drive, the fixed InstallMacOSXLion.dmg .
Then use the open-source tool dmg2img to convert the broken DMG to a raw ISO: You are not alone
For users trying to revive older Mac hardware, few things are as frustrating as a corrupted or broken DMG file.
The for an unmodified, clean Mac OS X 10.7.2 InstallESD.dmg (directly from Apple) is: cd ~/Downloads dmg extract MacOSXLion1072
If you’ve landed here searching for “Mac OS X Lion 1072 dmg file fixed,” you are likely staring at an error message like “The following disk image failed to mount – no mountable file systems” or “This copy of the Install OS X Lion application can’t be verified. It may have been corrupted during downloading.”