You can recover from a null key error.
This error can happen on WebSphere systems if the server's SPN identity (for example, FNCEWS_mysys@MYDOM.COM ) cannot be found in the Content Platform Engine server's currently configured keytab.
It can also happen if the keytab file itself cannot be found for some reason, such as using the default keytab, but that keytab was created by one user and the app server is running as another user account (a particular problem if the app server is running as a Windows service). One fix for this is to specify the keytabPath option for the KrbServerLoginModule, for example, keytabPath="c:/config/keytab".