imposible to have root with stock kernel and stock firmware?

Im having strange issues with root and super su, when i install cf auto root on a brand new fresh stock firmware at the next few hours super su suddenly sais:
There is no SU binary installed, and SuperSU cannot install it. This is a problem!

i know that changing the kernel fixes this... but cant i stay with root & stock kernel and firmware...?

Warning: "Camera failed" imposible to solve but dialing *#0*# the camera works

Hi, I have a problem with my front camera in the Galaxy S7 (SM-G930F). It doesn't work and every time that I enter in the front camera appears the message "Warning: Camera failed"



The Rear camera works perfectly but since I've bought the S7 I never couldn't use the front camera



Here is what I have tried:

- Force Stop, Clear Data, Clear Cache, and Clear Defaults

- Clear Cache Partition in Recovery

- Factory Reset through Settings

- Factory Reset through Recovery

- Installed 3rd party camera app

- Installed another OEM ROM through Odin

- Repite everything



And the camera never work.



But.... by entering *#0*# into the dialer and picking Front cam the camera works perfectly and I can take a pictures. but through the app it doesn't work

Another thing that I can do it is, install the Dual-camera MODE and I can use the both two cameras at the same time although the front camera locks very blurry but it is another problem





I need to know if it is a hardware problem or a softwared problem. I don't know if I replace the front camera It will work.