The session is terminted

[ivy1234]

I use Redhat 3 and ERP system on it , users always report to me their session is terminated ( the error as below ) , then exit he system . I ( with root user ) also encounter the problem , when it happens , it logout me to the shell , I can't find any error in database ( ERP) log , can advise what is the possible reason of the error ? thx


Session terminated, killing shell... ...killed.