In my sandbox I had the Compontent set Groups in my Lighting Community Builder .  It contained things like GroupBanner (for chatter)... but in my Production I do not.  I am guessing it is a setting I am missing somwhere.  Anyone know where?

I' m banging my head.  I have got a button to allow Leaders to blast a Chatter post when we have updates.  However to make it easier on our users to get it, we are having them follow a User that just blast these update.

The Leaders are admins (as am I) and have it checked to allow "Insert System Field Values for Chatter Feeds" in our profile and in the code I have

   
        FeedItem post = new FeedItem();
        String s = 'THe Message';
        post.ParentId = landingChatterGroup.Id;
        System.debug('Concierge.Id ' + Concierge.Id);
        post.createdById = Concierge.Id;
        post.Body =s;
        post.Type = 'TextPost';
       
    insert post;

I am getting INSUFFICIENT_ACCESS_ON_CROSS_REFERENCE_ENTITY, insufficient access rights on cross-reference id: [

What am I missing?  The user is a Manager in the chatter group I am trying to add the post to.

I' m banging my head.  I have got a button to allow Leaders to blast a Chatter post when we have updates.  However to make it easier on our users to get it, we are having them follow a User that just blast these update.

The Leaders are admins (as am I) and have it checked to allow "Insert System Field Values for Chatter Feeds" in our profile and in the code I have

   
        FeedItem post = new FeedItem();
        String s = 'THe Message';
        post.ParentId = landingChatterGroup.Id;
        System.debug('Concierge.Id ' + Concierge.Id);
        post.createdById = Concierge.Id;
        post.Body =s;
        post.Type = 'TextPost';
       
    insert post;

I am getting INSUFFICIENT_ACCESS_ON_CROSS_REFERENCE_ENTITY, insufficient access rights on cross-reference id: [

What am I missing?  The user is a Manager in the chatter group I am trying to add the post to.