

Why 'Your clock is ahead' on Mac & How to Fix? Check from the Apple menu > System Preferences > Date & Time, and you can simply choose Set date and time automatically to avoid clock errors on Mac. Such incompatibility may cause the App Store can't download and update applications. In case the date and time are wrong on your computer, there is a discrepancy between your Mac and the Apple server. You can head to the system status page to check whether the Mac App Store is available now. If so, you may be unable to use the Apple store for a while until the Apple system resumes work. Perhaps, there is an outage of the Apple system. You can turn WiFi off and reconnect it, use an ethernet cable, or reset network settings. Therefore, if the App Store can't load on your Mac, perhaps, you haven't established a quality WiFi connection on the Mac.

To update macOS and download apps in the App Store, it needs a stable internet connection to load the resource from Apple's servers. Switch to another account/create a user account.
