You may get an S837-08 abend transferring a multi-volume tape dataset with CA XCOM for z/OS after five volumes have been transferred.
This problem can happen if TAPE=YES was not specified. TAPE=YES must always be specified if the remote file is on tape. If this is not specified, then tape parameters such as LABEL, SEQ#, TAPE and VOLCT are set to their default values.
If TAPE=YES is not coded, CA XCOM assumes the remote file is on DASD. The VOLCT always defaults to five both for DASD and TAPE. That is why a multi-volume tape transfer may abend after five volumes.