a downloaded scrip worked for a day but the next day the script didnt work anymore.

so im new whit coding/game making and i dont know how to fix this errors.

my first error occurred when i saved unity for the day and went to sleep, the next day none of the scripts worked and i was really confused so i deleted them and then put them back in scripts still didnt work.
i went to the console fixed the errors when new ones apeared and i dont know how to fix them.
i dont know what to do now.

could it be that the charactercontroll2D is too old or something?

You have code errors in player.cs. Those need to be resolved. The problem is probably not in CharacterController2D.