This error message from tar(1) indicates that the checksum of the directory and the files it has read from tape does not match the checksum advertised in the header block. Usually this message indicates the wrong blocking factor, although it could indicate corrupt data on tape.
To resolve this problem, make certain that the blocking factor you specify on the command line (after -b) matches the blocking factor originally specified. If in doubt, leave out the block size and let tar(1) determine it automatically. If that remedy does not help, the tape data could be corrupted.