First of all, this problem is related to time. Now the latest system version of Mac has reached 10.15, and Sierra is the code name of 13. Check the release date of version 10.13 on the Internet, and then change the date to a similar date. In addition, there are many operations on the Apple system that are related to the date. For example, after installing a black apple, the system time is inconsistent with the current time. Even if the network is connected, the Internet cannot be accessed and the time must be corrected. The solution: 1.Open Terminal (Utilities → Terminal) 2.Enter date 071014102018 (don’t care about the disconnection in the picture here, just enter the command directly, the command time can be changed by yourself, mainly within a certain period of time, the date range is relatively large) . date 062614102014.30 06 is the month, 26 is the day, 14 is the hour, 10 is the minute, 2014 is the year, and 30 is the second; you can change it according to this rule, the sy...
