GPM064I

Explanation
The DDS host server has detected that an important
component of the server address space has encountered a permanent
error. In this case, the component that accepts incoming session requests
via UNIX domain sockets (for
example, PM of OS/390® APPC
clients) has abnormally terminated.

System action
The component is restarted. After 5 unsuccessful
requests. the component is deactivated.

System programmer response
Make sure that all required prerequisites
for the component are active and operational (mainly z/OS UNIX System Services).
Make
sure that the pathname /tmp/gpmserve/pmos390
 is
free and can be used by the DDS server.
If more than one instance
of the DDS host server is started, this message will appear for all
instances but the first one, because the UNIX socket
pathname cannot be shared by different servers. In this case, always
the first server will handle incoming UNIX session
requests.
This message might be caused by using
the old OS/2 version
of PM of OS/390 which is
not supported anymore.  Please, insure that only the Java™ Edition of RMF™ PM
will be used.

Source
Resource Measurement Facility™ (RMF) - Distributed Data Server (DDS)