If you're having problems backing up or restoring from iCloud, this is likely not an issue with WhatsApp but with the iCloud account. If you need help with iCloud, please contact Apple Support.
Can't create a backup
If you're unable create an iCloud backup:
- Verify you're signed in with the Apple ID that you use to access iCloud.
- Verify iCloud Drive is turned on.
- If you've turned on iCloud Drive for any device using your Apple ID, you would need to update to iOS 9 or later to back up.
- Verify you have enough available space on your iCloud account to create a backup.
- If you're attempting a backup on a cellular data network, make sure you've enabled cellular data usage for iCloud.
- Perform a manual backup by going to WhatsApp Settings > Chats > Chat Backup > Back Up Now.
- Attempt the manual backup on a different network. Preferably the network you connect to the most.
Can't restore a backup
If you're unable to restore an iCloud backup:
- Verify you're attempting to restore data from the same phone number and iCloud account that the backup was created on.
- Verify there's enough space on your iPhone to restore the backup. You need to have at least 2.05 times the space available in your iCloud account and on your phone than the actual size of your backup.
- If the backup was created using iCloud Drive, you’ll only be able to restore that backup on an iPhone with iOS 9 or later.
- If you've turned on iCloud Drive for any device using your Apple ID, you won't be able to restore data on your iPhone unless it has iOS 9 or later.
- Attempt the restoration from a different network. Preferably the network you connect to the most.
- Sign out of iCloud and restart your iPhone by turning it off and on. Then, sign back in to iCloud and try the restore again.