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Same as before. Look at line 57, find the variable and find why it does not have a valid value.

What variable has the null value? Where should that variable have been assigned a value?

There is a variable with a null value on line 9. Look at line 9 in the your source and see what variable is null. Then backtrack in the code to see why that variable does not have a valid value.
If...

Please copy the full text of the error message and paste it here.

BTW NullPointerExceptions happen when a program is executed, not when it is compiled.