I have got a weird issue. I modified the third person controller script, while disable the default third person controller script. After testing it, it worked fine so I then removed the default one and use mine instead. However, when played, the camera didn’t follow my character. My question isn’t about the script I modified. I wonder that disabling a component(and not enable it anywhere in the script) is perfectly equal to removing a component. thank you for any help in advance 
never mind that already, I accidentally put a require statement in one of the script, got it fixed