Server error occured

[thereallinkieXD]

I am really hoping I could get some help. I got a Galaxy S5 active about a year ago. Front camera working and everything. I gave the battery to my friend and the phone stayed off for about 4 months or 5. I have been plugging it into a wall adapter to see if it would power on, but it didn't. I used other phone batteries and they worked if you tilted so that the pins connected. 2 days after that, I have bought another battery. I reset the device and when I wanted to use the camera, I got "Warning server error occured. Please restart the camera" every time I tried to open the selfie cam. But when I used the back camera, it worked just fine. I updated to 6.0.1 via ADB and the problem still exists. I factory reset again, cleared the cache, cleared the camera's data, and nothing. It still gives me an error. I take pictures quite a lot with family, so any help on how to fix this will be greatly appreciated