invalid key length, key number <num>, length <num>

  Explanation:  The key size is incorrect for the data type, or
  the total key size is greater than 32,767.

  User Action:  Specify the correct key field size.  Size must be
  less than or equal to 32,767 for character data; 1, 2, 4, 8, or
  16 for binary data; and less than or equal to 31 for decimal.
  Also, only ascending or descending order is allowed.