Troubleshooting in IBM WebSphere Application Server

Problem 1:
ADMU0116I: Tool information is being logged in file
ADMU0128I: Starting tool with the Custom01 profile
ADMU3100I: Reading configuration for server: nodeagent
ADMU0111E: Program exiting with error:
           ADMN0022E: Access is denied for the stop operation on Server MBean
           because of insufficient or empty credentials.
ADMU4113E: Verify that username and password information is correct.  If
           running tool from the command line, pass in the correct -username
           and -password.  Alternatively, update the <conntype>.client.props
ADMU1211I: To obtain a full trace of the failure, use the -trace option.
ADMU0211I: Error details may be seen in the file:

 It may be happened when  u may forget to specify  credentials for dmgr.
Node may not synchronize with dmgr correctly. So, stop server of that node and node agent in dmgr Admin console. Then do synchronization by using

 thank u. comments & feedback r most welcome.
tell me which topics in websphere application server 8.5 u want.