anchor.diff:  
               lager:info("~p: Message after send interposition is: ~p", [node(), Message]),
   
  -            gen_server:reply(From, ok),
  +            case From of 
  +                undefined ->
  +                    ok;
  +                _ ->
  +                    gen_server:reply(From, ok)
  +            end,
   
               {noreply, State#state{vclock=VClock}};
           Message ->
  
positive.code:                                     Connections)
              end,
  
              gen_server:reply(From, Result),
  
              {noreply, State#state{vclock=VClock}}
      end;
  
negative.code: 
      case Message of
          undefined ->
              %% Store for reliability, if necessary.
              case proplists:get_value(ack, Options, false) of
                  false ->
                      ok;
                  true ->
                      %% Acknowledgements.
                      RescheduleableMessage = {forward_message, From, Name, Channel, MessageClock, PartitionKey, ServerRef, OriginalMessage, Options},
                      partisan_acknowledgement_backend:store(MessageClock, RescheduleableMessage)
              end,
  
              %% Fire post-interposition functions.
              PostFoldFunUndefined = fun(_Name, PostInterpositionFun, ok) ->
                  PostInterpositionFun({forward_message, Name, OriginalMessage}, {forward_message, Name, Message}),
  