$ ./tieBoardTree.pl
Can't locate object method "TIESCALAR" via package "Tie::File" at
        ./tieBoardTree.pl line 47 (#1)
    (F) You called a method correctly, and it correctly indicated a package
    functioning as a class, but that package doesn't define that particular
    method, nor does any of its base classes.  See perlobj.
    
Uncaught exception from user code:
        Can't locate object method "TIESCALAR" via package "Tie::File" at ./tieBoardTree.pl line 47.