Some older `tail' implementations also support an
obsolete option `+COUNT' with the same meaning as `-+COUNT'. POSIX
1003.1-2001 (*note Standards conformance: does not allow these
options; use `-c COUNT' or `-n COUNT' instead.
Find "tail +N" (N is 6, or other number, or a variable such as $Skip) in your file, change it to "tail -n +N".
Then run the file, it may be wrong again and hint " Error in check sums COUNT1 COUNT2".
find COUNT2 in the file, change it with COUNT1.
It may work