Connection to system system_name failed with exception exception.
If you are connecting to your CICSPlex SM WUI server CMCIPORT for the first time, check the WUI server MSGUSR log for additional error messages. If the log contains the messages DFHXS1111, DFHWB0361 and DFHAC2003, then ensure your CICS Explorer userid has permission to attach the CWXN and CWWU transaction identifiers.