Why can I not update apps?

Sign out of the App Store and sign back in. If the app was purchased with a different Apple ID, you need that ID to update it.

How do I fix 'An unknown error has occurred'?

This vague error is usually a server or authentication issue. Check Apple System Status, sign out/in of your Apple ID, verify date/time, and try on a different network.

Mac App Store Errors — Cannot Download, Update, or Connect Issues

Warningappstore

Overview

Fix Mac App Store errors including unable to download apps, update failures, blank App Store screen, and Apple ID authentication issues.

Key Details

App Store errors often manifest as 'Cannot connect to the App Store' or silent download failures
The App Store cache can become corrupted, causing blank screens or loading failures
Apple ID authentication issues can prevent purchases and downloads
Country/region mismatch between Apple ID and App Store can block app availability
macOS compatibility: some apps require newer macOS versions and will not install on older systems

Common Causes

Corrupted App Store cache preventing content loading
Apple ID authentication token expired or invalidated
Network connectivity issue or Apple server outage
Date and time settings incorrect, causing SSL certificate validation failure
VPN or proxy interfering with Apple's content delivery network

Steps

1Check Apple System Status page (apple.com/support/systemstatus) for App Store outages
2Sign out and back in: System Settings > Apple ID > Sign Out, then sign back in
3Clear App Store cache: defaults delete com.apple.appstore in Terminal, then reopen App Store
4Verify date and time are correct: System Settings > General > Date & Time > set automatically
5Disable VPN/proxy temporarily to test direct connection to Apple servers
6Delete App Store cache folder: rm -rf ~/Library/Caches/com.apple.appstore then restart App Store