Some users of Mac computers running MacOS Sierra and MacOS High Sierra have reported issues when trying to log in to an Apple ID or iCloud via System Preferences, as well as problems accessing iCloud.com using Safari. In addition, Safari fails to load Apple websites that require an Apple ID login, displaying the error message “Safari can’t establish a secure connection to the server ‘idmsa.apple.com’.”

If you're encountering any of these error messages on MacOS High Sierra or macOS Sierra, installing an Apple certificate through Keychain Access should help resolve the issue:

• Error in MacOS iCloud System Preferences: “You can’t sign in at this time. Try signing in again.”
• Error in Safari when accessing iCloud.com: “Connection error : iCloud encountered an error while trying to connect to the server.”
• Safari error when visiting Apple ID-related sites: “Safari Can’t Open the Page : Safari can’t open the page ‘http://miracleart.cn/link/a3444e049a3a88560cba360c18001932’ because Safari can’t establish a secure connection to the server ‘idmsa.apple.com’

One possible solution for idmsa.apple.com connection errors in Safari is to use an alternative browser such as Chrome, Firefox, or Brave. However, this won't address the issue within System Preferences or fix the Safari-specific errors.

Note: This issue only affects MacOS Sierra (10.12.x) and MacOS High Sierra (10.13.6) with Safari 13. Newer versions of MacOS are not affected and do not require any fixes.

Fix “Can’t Establish Secure Connection with idmsa.apple.com”, iCloud, & Apple ID Errors on Safari in MacOS Sierra, High Sierra

To resolve the Safari idmsa.apple.com connection errors, Apple ID usage issues, and iCloud errors, follow these steps using a working web browser on your affected MacOS device:

1. Visit the Apple certificate authority page: http://miracleart.cn/link/d3db718a011f94f39dd49b576d785b08
2. Download the intermediate certificate labeled “Apple IST CA 2 – G1 Certificate” (direct download link: AppleISTCA2G1.cer)
3. Once downloaded, locate the AppleISTCA2G1.cer file in your Downloads folder and double-click it to install into Keychain Access
4. The certificate “Apple IST CA 2 – G1” should now appear in Keychain Access
5. Restart Safari to fix the connection errors. Optionally, restart your Mac to also resolve iCloud-related issues in System Preferences

Many Mac users still operate older versions of the operating system like MacOS High Sierra and MacOS Sierra, either due to software compatibility needs, hardware limitations, personal preference, or other reasons.

As Apple no longer provides updates for these older versions of MacOS, users often need to troubleshoot and resolve such issues themselves. We appreciate mjtsai and @metaning for sharing this solution, which was originally discussed on discussions.apple.com.

The above is the detailed content of Fix iCloud Errors & “Can’t Establish Secure Connection with idmsa.apple.com” on MacOS Sierra & High Sierra. For more information, please follow other related articles on the PHP Chinese website!