I'm trying implement SSO and I'm having some trouble. I've been dealing with most of it but now I've got this: 01:00:44,021 ERROR [JBossWebRealm] Error during authenticate java.lang.NullPointerException at java.util.Arrays.mergeSort(Arrays.java:1144) at java.util.Arrays.mergeSort(Arrays.java:1155) at java.util.Arrays.sort(Arrays.java:1079) at org.apache.catalina.realm.GenericPrincipal.(GenericPrincipal.java:96) at org.jboss.web.tomcat.security.JBossGenericPrincipal.(JBossGenericPrincipal.java:71) at org.jboss.web.tomcat.security.JBossWebRealm.getCachingPrincipal(JBossWebRealm.java:675) at org.jboss.web.tomcat.security.JBossWebRealm.authenticate(JBossWebRealm.java:409) at org.jboss.web.tomcat.security.login.WebAuthentication.login(WebAuthentication.java:93) ... rest of trace truncated. The GenericPrincipal code looks like this around line 96: | 92 if (roles != null) { | 93 this.roles = new String[roles.size()]; | 94 this.roles = (String[]) roles.toArray(this.roles); | 95 if (this.roles.length > 0) | 96 Arrays.sort(this.roles); | 97 } | Does this mean that one of my Roles is null? Where are the roles coming from? There are 2 places where I can specify roles that I know of. One is in the LoginProvider that I wrote. The other is in sso-cfg.xml. The LoginProvider will return at least "Other" if no role exists for an otherwise authenticatable user. I'm using UsernameAndPasswordLoginModule. Can anyone help please? thanks. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4215104#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...