[Q] [HELP] Getting "warning:Camera Failed" error popup when camera app is opened! topic

I keep getting this when I try to open my camera or any other third party camera application .
i tried clearing the cache , factory reset, hard reset and also removed Sd card n tried, still nothing.
But i am able to use the front camera on snapchat or on a hangout video call alone. If i tried to switch cameras ,they would just crash. :(
A fix would be really helpful!!

PS:
i bought the phone elsewhere and cant return it or exchange it :(