IBM® Integration Busis a 64-bit executable and as such uses z/OS® memory objects above the bar. You must allow the integration node to access storage above the bar.
Your installation might have customized the SMFPRMxx member of SYS1.PARMLIB, or the IEFUSI exit to provide a default limit for jobs using virtual storage above the 2 GB bar. Check these limits give sufficient memory for a integration node.
//EGENV EXEC PGM=BPXBATA8,REGION=0M,TIME=NOLIMIT,MEMLIMIT=4G