Every time i test my game,my character flies upward infinitely

Im making a game,and Im using the prefab first person controller,but every time I play,my character starts flying upwards,and doesnt stop ever.What should i do?(I dont know if this is a coding problem,but if you need code shown,just ask)

You may want to go to Edit > Project settings > Physics. This might show gravity as negative. You can edit the gravity to fit your needs.