How to Fix "iCloud Backup Could not be Completed" Issue?

If you get a messages says that your iCloud backup could not be completed, then make sure that you are connected to the internet with Wi-Fi. If possible, you can try connecting to a different Wi-Fi network. Otherwise, see if you have enough iCloud storage for your backup, if not, then get more storage space.

You can connect your device to a Wi-Fi network, including open, secure and hidden networks. To connect to Wi-Fi networks, tap "Settings" and tap "Wi-Fi and move slider from left to right to turn ON "Wi-Fi". Your device will search for available Wi-Fi networks. Tap the name of the Wi-Fi network that you want to join. Once you have joined the network, you will see "Check mark" icon located next to the network and network sign in the top left corner of your display.