Your iPhone should be restarted. Many firmware-related difficulties can be resolved with a simple reboot of the device. Here's how to reset an iPhone 6s for those who need it:
- Hold the Power (Sleep/Wake) button down until the red slider appears.
- To totally turn off the iPhone, drag the slider.
- Press and hold the Sleep/Wake button until the Apple logo displays on the screen after the iPhone has been turned off.
Set the network settings to default. Resetting your network settings will also reset network information, such as your Wi-Fi network and passwords, cellular settings, and VPN and APN settings. As a result, make a copy of this information before you start. Go to Settings->General->Reset-> Reset Network Settings to reset your network settings.
Turn off Airplane Mode. Make sure that the Airplane mode is turned off. Simply go to Settings->Airplane Mode on your iPhone. Toggle the switch to turn the feature OFF, if needed
