Older Mac OS Installers failing

By: Brad McMillan, Computer Support Specialist (Mac and Windows)

November 1, 2019

If you are trying to install an older OS on a Mac you may encounter an error regarding the installer being damaged. It is a certificate issue.

A quick workaround is to simply set your system clock to 1/1/2019 or better yet download the updated installer referenced in the tidbits.com article.

For more detailed information on this issue, please see https://tidbits.com/2019/10/28/redownload-archived-macos-installers-to-address-expired-certificates/ .

Published on  and maintained in Cascade.