While DIE000 is a generic ABEND, we have encountered a repeatable failure for a specific reason. If two or more VM:Operator macros execute the TCP/IP utility commands PING or TRACERTE at the same time, it is possible to see the DIE000 ABEND. IBM confirmed that these TCP/IP commands are not thread safe (i.e. CMS multitasking compliant) and will have issues if executing simultaneously.
Symptomatically, the message "DTCPIN0039E Unable to setup external interrupt handler" has been seen when the DIE000 ABEND has occurred. If the PING or TRACERTE commands target an unresponsive IP address this greatly increases the likelihood that an ABEND will occur.