This message is displayed in the Jes Syslog for the application and not in the TPX log.
If Generic resource is not turned on, This message may be ignored. If Generic Resource is turned on this message indicates a missing module that is in CA common services.
TPX communicates with the Coupling Facility via a module 'LXCFMAIN'. This module is in the common services - CA90s - residing in LPA or linklist library. If a message similar to:
TPXL5501 message with Rc=00000016 Rsn=00000031 is observed, make sure module 'LXCFMAIN' is available to TPX. Usually adding a steplib to the CA90 CAILIB will correct the error.