ContextManage E createInstance Could not load class: com.ibm.ws.security.auth.ContextManagerImpl

Issue :: 

while starting the dmgr or JVM or Nodeagent in websphere 7.0 causing problems

ContextManage E   createInstance Could not load class: com.ibm.ws.security.auth.ContextManagerImpl

Cause ::

Cause: security.xml file is corrupted 

Résolution ::

       please check the security.xml file size . if its corrupted it show as 0 size and check the last date time of the file  .

       If you found the file is corrupted . 

You could replace the corrupted file with the same file from the Deployment Manager's repository. 

Restart whole cell ( nodeagent and dmgr and JVM's ) its will fix the issue .