020

Explanation
The error occurred during processing of a BDAM
OPEN macro instruction.
The control program found that the DCBMACRF
field of the data control block did not contain an A, K, or I, or
an attempt was made to open a BDAM data set that contained zero extents.

System action
The system ends the task.

System programmer response
If the error recurs and the program
is not in error, look at the messages in the job log for more information.
Search problem reporting data bases for a fix for the problem. If
no fix exists, contact the IBM® Support
Center. Provide the JCL and the program listing for the job.

Programmer response
In the first case, make sure that A, K,
or I is specified in the MACRF operand of the DCB macro instruction.
 Verify that the DCBMACRF field was correctly modified by the problem
program before the opening process.  After making corrections, reassemble
the program and run the job step again.
In the second case,
create the data set before attempting to open it as a BDAM file.

Source
DFSMSdfp