BFB

Explanation
During JES3 abnormal termination recovery processing,
JES3 was unable to invalidate the spool space allocation checkpoint
record (PTC). The invalidation failed due to an error in the checkpoint
access method or an unrecoverable I/O error in the checkpoint data
set(s).
Message IAT6352 accompanies this completion code. JES3
could not invalidate the spool space allocation checkpoint record
(PTC) during JES3 abnormal termination recovery processing.
When
message IAT1025 accompanies this completion code, JES3 could not invalidate
the only copy or both copies of a partition track allocation table
(PTAT) during JES3 initialization or after JES3 failsoft processing.

System action
After issuing the message, JES3 ends. IAT6352
contains the checkpoint access method return code, which identifies
the error.
If message IAT1025 appears, the system writes an
error record to the logrec data set.

System programmer response
If the problem occurs in JES3, take
a system dump by specifying DUMP=MVS on the OPTIONS card in the initialization
deck Make sure that the failing job step includes a SYSABEND statement.

Programmer response
Using message IAT6352, analyze the return
code and correct the error, then restart JES3.
For message IAT1025,
analyze the error record in the logrec data set and the accompanying
messages. In case the error is caused by a bad track, assign another
track to the checkpoint data set and restart JES3 with a warm start.
 Otherwise, reallocate the checkpoint data set and perform a cold
start.

Source
JES3