Dan Frakes wrote a guide to creating OS X 10.11 El Capitan install disks for Macworld. Those who have created any bootable install disks for OS X will need to recreate them with the new installers. The new installers are signed with a certificate that expires on 7 February 2023, so it will be quite a few years before Mac users are affected again. Scroll down to the OS X installer you want and click Download. Enter your App Store password if prompted.

Open the App Store app by choosing Apple menu > App Store.Ĭlick the Purchased tab.

These installers have names like Install OS X El Capitan and Install OS X Yosemite.

Delete any old OS X installers in the Applications folder or in other locations (be sure to look on external hard drives too if the App Store detects an old installer, it won’t let you get a new one).

Happily, this is an easy problem to fix ahead of time:

But if youĭownloaded an OS X installer in case of trouble, you may be in for a surprise the next time you try to use it. Most affected apps have already been updated with the new certificate.

This certificate expired on 14 February 2016, causing error dialogs and preventing some apps from launching. When used to sign an app, the certificate enables OS X to confirm that the app has not been corrupted or modified by an attacker. The Apple Worldwide Developer Relations Intermediate Certificate is required for all apps in the Mac App Store, including OS X installers. #1644: Explaining Mastodon and the Fediverse, HomePod Software 16.3 and tvOS 16.3, GoTo breachįile this one under “Obscure problems that could ruin your day.” TidBITS reader Randy Singer alerted us that due to an expired certificate, OS X installers downloaded prior to 14 February 2016 won’t work.#1645: AirPlay iPhone to Mac for remote video, Siri learns to restart iPhones, Apple's Q1 2023 financials.1646: Security-focused OS updates, Photos Workbench review, Mastodon client wishlist, Apple-related conferences.1647: Focus-caused notification issues, site-specific browser examples, virtualizing Windows on M-series Macs.#1648: iPhone passcode thefts, Center Cam improves webcam eye contact, APFS Uncertainty Principle.

Download mac os el capitan installer