SA03 abend can occur at CV shutdown or startup in some situations.
The SA03 at shutdown indicates that the main TCB for the CV is trying to end but there is an active subtask TCB still active, which is not related to Multi-Tasking.
This can commonly occur at CV shutdown when:
To resolve this:
Shutdown MQ-Series subtask or other subtask which is still active when the shutdown is attempted, before issuing the CV SHUTDOWN command.
An SA03 can also occur at startup. The main causes for that are:
To resolve these, ensure that the SVC and CV startup modules are assembled with the current operating system libraries, and the CAIRIM has been run to load the SVC before starting the CV which references it.