Recommended methods:
After the "set" –> "WiFi" –> enters the current WiFi entry, click the next exclamation mark, and then click DNS to delete the original setting 8
8.8.8 is OK.
1 The easiest way is to restore the network to try
Click "Set" on the Apple phone desktop to find "General" and then click "Restore" –> "Restore network Settings" and restart the phone.
2) Reset Access Restrictions
Also click "Set" –> "General" –> "Access Restrictions" on the iphone, turn on access restrictions for 5 seconds, and then turn off access restrictions.
3) Reset the current WiFi
or after clicking "Set" in the Apple phone and finding "WiFi" and then entering the WiFi connection, we click into the current wifi–> "ignore this network" to reset the current WiFi, then reboot the IPhone5 and reconnect to WiFi.
4) Check your time, as well as the timezone
Go to IPhone5 "setting" –> "General" –> "date and Time" –> turn off automatic settings. Turn on automatic settings if the date and time are correct.
5) Reload ibooks
Try uninstalling the ibooks and then installing ibooks again.
6) Reset Date and time
Set –> Universal –> Date and time –> turn off automatic settings
Add
A friend said my iphone5s also encountered such a situation, it is recommended that you shut down the restart, and then open flight mode, the use of WiFi connection to the App store, should be back to normal. Turn off flight mode after normal,