Getting error in SolrNet

Question

Getting error "The remote server returned an error: (400) Bad Request."

public void IndexPlayers()
{
    new SolrBaseRepository.Instance<Player>().Start();

    var solr = ServiceLocator.Current.GetInstance<ISolrOperations<Player>>();
    var players = new PlayerRepository().GetPlayers();

    solr.Add(players);
    solr.Commit();
}

while add players in Solr .