Have you applied any APARs or PTFs?

APARs and PTFs can occasionally cause unexpected problems with IBM® MQ. These fixes can have been applied to IBM MQ or to other z/OS® systems.

If an APAR or PTF has been applied to IBM MQ for z/OS, check that no error message was produced. If the installation was successful, check with the IBM support center for any APAR or PTF error.

If an APAR or PTF has been applied to any other product, consider the effect it might have on the way IBM MQ interfaces with it.

Ensure that you have followed any instructions in the APAR that affect your system. (For example, you might have to redefine a resource.)