If you can't use LINE for any of the following reasons after restoring from an iTunes/iCloud backup, try offloading and reinstalling the app.
Note: Your data will remain intact even if you offload the app.
• An error appears and you can't use LINE.
• An old email address appears and you can't use your LINE account.
• Entering your passcode doesn't unlock the app.
• The login screen repeatedly appears.
• You have notifications turned ON, but are not receiving them.
To offload and reinstall LINE:
1. On your phone, tap Settings > General > iPhone Storage.
2. Tap LINE in your list of apps.
3. Tap Offload App > Offload App.
4. After offloading the app, tap Reinstall App.
Let us know if we can make it better.