java.lang.RuntimeException: Fail to Connect to camera service

I tried to make an app than can switch my camera flash on and off. The code I have atm looks like this:

Camera flash;
Camera.Parameters params;

flash = Camera.open();
params = flash.getParameters();

params.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);        
flash.setParameters(params);

And in the manifest xml:

<permission android:name="android.permission.FLASHLIGHT"  

android:permissionGroup="android.permission-group.HARDWARE_CONTROLS"
          android:protectionLevel="normal" />

<permission android:name="android.permission.CAMERA"> </permission>

Everytime I run the code, the app crashes at "flash = Camera.open();" with this error:

java.lang.RuntimeException: Fail to Connect to camera service

What am I doing wrong?