The Apple 7plus front camera can be used again after restarting.

There is an error or bug in the camera software, so you can't take pictures. Generally, you can return to normal by restarting your phone and then turning on your camera. If it doesn't work properly after restarting, you can try to install a third-party camera software for testing. If you can take photos normally, it means that there is something wrong with the camera software of the system, and you need to reset or upgrade the system to make the camera software return to normal. There is a bug in the mobile phone system, so you can't take pictures. You still need to reset the system or upgrade the system to solve it. Mobile phone hardware failure makes it impossible to take pictures, such as camera hardware failure, internal wiring failure, motherboard chip failure, etc. It is recommended to contact Apple's official after-sales maintenance.