websphere liberty - Error attempting to view files and logs for Bluemix app -

i want view files , logs bluemix application, when select overview page app, shows message:

bxnui0045e: not retrieve files or logs 'xxx' application using instance '0'. see troubleshooting topics in ibm bluemix documentation check service status, review troubleshooting information, or information getting help.

i looked @ troubleshooting topics found nothing helpful. message trying tell me, , how can fix problem can see files , logs app?

if application failed start or crashed, bluemix ui can not used retrieve files , logs. recommend use command line tool.

if application failed start or crashed, can logs by:

cf logs <appname> --recent

if application started , running properly, can view files (including logs server or application writes) by:

cf files <appname> cf files <appname> <path>