In the past, Apple made older OS versions difficult to find. The standard "Download" button in the App Store usually redirects to the newest compatible OS. However, Apple now maintains a hidden support section for legacy software.
Safety Warning: Avoid downloading macOS DMG files from third-party "warez" sites or torrent trackers. These files are often modified to contain malware or bloatware. Always prioritize official Apple sources. Mac Os Sierra 10.12.6 Dmg File Download
createinstallmedia errors:
“Volume is not a valid volume mount point”: In the past, Apple made older OS versions difficult to find
Corrupted DMG or checksum mismatch:
If you or your Apple ID downloaded Sierra before it was removed from the App Store in late 2019: createinstallmedia errors: