IRR63012I

Explanation
The block that is the object of a FORMAT or DISPLAY
command is not a valid index block. The following tests are made for
a valid index block: The first index block identifier (offset 00) must be X'8A'.
The second index block identifier (offset 03) must be X'4E'.
The displacement to free space must be greater than the displacement
to the last entry.
The displacement to free space must be less than 4096.
The last byte before free space (the end of block delimiter) must
be X'0C'.
The entry identifier for all entries must be X'21' or X'22',
except for the identifier of the last entry in a level 01 block, which
must be X'20'.
The lengths of all entries must be correct.
The pointer section identifier—also called the E(P) byte—of each
entry must be X'62' or X'66'.

System action
The command is ignored.

Programmer response
Make sure the RBA specified on the READ
command is that of an index block. Use the LIST and REP subcommands
of READ to fix the index block.

Problem determination
Record message number and RBA of READ
command. Get a dump of the area you are trying to DISPLAY or FORMAT
and check the data of the index that had the error. Contact your IBM® support center.