If the camera failed problem on Samsung is still not solved, then the next thing you should do is a factory reset.But before that create a backup of your important data as all will be gone after this step is completed.Your Samsung device will restart and then you can check if the camera failed problem has been fixed.
In case the camera failed problem on Samsung device is not solved with the steps mentioned above then try deleting the cache partition of the device.
Sometimes, the system cache files may be the culprit.
Once the files have been deleted, go back to the camera app and check if it starts working without errors.
The smart stay feature is great to use, but many Samsung users have reported that the problem appears when they are using Smart Stay.
Use the volume down key to highlight Restart and then select it by pressing the Power key.
Samsung Problem Solving
Once your phone restarts, check if the camera works as expected.
But it can be frustrating when you want to capture a moment and all you are left with is a message on the screen that says “Warning: Camera failed”.
Now you don’t have the option to do anything but close the camera and try re-opening it hoping that the error solves on its own.
In a situation like this, it is difficult to point out whether the problem may lie with a third party app that you have installed or the software of the camera itself.
When you restart your device in Safe Mode, all the third party apps will be disabled.