OS/400 programming considerations
If you have compiled programs for releases of WebSphere MQ for iSeries earlier than V4R4, you will have linked to AMQZSTUB and, possibly, AMQVSTUB. These libraries are provided at this release for compatibility purposes; you do not need to recompile your applications.
These libraries provide support for the default connection handle (MQHC_DEF_HCONN). This is no longer provided by the standard V4R4 libraries. However, the libraries provided at this release for compatibility purposes do not support all new features (for example, MQCONNX, MQCMIT, and MQBACK).
When creating your program on OS/400, the QMQM activation group should not be used. The QMQM activation group is for the use of WebSphere MQ only.