You install or upgrade to Websphere MQ (WMQ) V7.1 or newer version on AIX platform. Then, you try to create a queue manger or start an existing queue manger, but it fails and an FDC file is generated.
The FDC file with the problem ID XC037021 is generated.
From the FDC file, you can see the following environment variable is set (at the bottom of the FDC, under the section "Environment Variables:").
This issue is caused by AMQ_SIGCHLD_SIGACTION.
It is an undocumented variable created for WMQ V5.3. For WMQ 7.1 or newer version, there is no need to set this variable.
WMQ 7.1/7.5/8.0 on AIX
Resolving the problem
Remove the environment variable AMQ_SIGCHLD_SIGACTION.
WebSphere MQ WMQ