Hi,

I am trying to automatically assign a new user to a Chatter Group called 'Everyone'.  The code below works as long as I do not select a role; however, when I select a role I get the following error.  Does anyone have a clue what this error means or if there is a code that can do what I am trying to do?

22:29:46.425
(425800000)|EXCEPTION_THROWN|[24]|System.DmlException: Insert failed.
First exception on row 0; first error: MIXED_DML_OPERATION, DML
operation on setup object is not permitted after you have updated a
non-setup object (or vice versa): CollaborationGroupMember, original
object: User: []
22:29:46.426
(426685000)|FATAL_ERROR|System.DmlException: Insert failed. First
exception on row 0; first error: MIXED_DML_OPERATION, DML operation on
setup object is not permitted after you have updated a non-setup object
(or vice versa): CollaborationGroupMember, original object: User: []

trigger User_trigger on User (after insert, before insert, after update, before update) {
    if ( Trigger.isInsert ) {    
        if ( Trigger.isAfter ) {
            List<CollaborationGroupMember> cgm = new List<CollaborationGroupMember>();              
            Id cgID = [ Select Id 
                      FROM CollaborationGroup 
                      WHERE Name = 'Everyone' LIMIT 1 ].ID;
System.debug('zzz: ' + cgID);    
            for ( user u: Trigger.new ) {
                cgm.add(new CollaborationGroupMember (CollaborationGroupId = cgID, MemberId = u.id));    
            }    
            insert cgm;          
        }
    }
}