How to fix an iPhone 7 iOS update error on Unable to Check for Update?

Wi-Fi connection issues can be resolved by forgetting or disconnecting from the network and then reconnecting. This is frequently required when the wireless network in use becomes corrupted and ceases to function. If you want to give it a shot, here's how to turn off your iPhone's Wi-Fi network.

1. From the Home screen, select Settings.
2. Choose Wi-Fi.
3. Navigate to your Wi-Fi network and then tap the I icon next to it for more details.
4. Choose to Forget This Network from the drop-down menu.
5. To confirm the action, tap Forget.
6. After forgetting your Wi-Fi network, restart your iPhone to refresh its memory and iOS, and then go back to Settings-> Wi-Fi to set up and reconnect your Wi-Fi network.