Attempt to upvalue index...

Hi,

 I have 3 errors:

1st error: When I restart my level,I recive an error that the index tried to upvalue “score” (a nil value).

In my “remove” function I removed my score 

score = nil 

2nd error: Same as the first one.Tried to upvalue a variable that was removed in my “remove” function.

3rd error: My previous score still remains on the screen after the level is restarted,and I don’t ant that,because,my score starts from zero again once the level is restarted.

Thanks