diff --git a/Assets/MainAssets/Scripts/Managers/CrowdBotSim_TrialManager.cs b/Assets/MainAssets/Scripts/Managers/CrowdBotSim_TrialManager.cs
index 36df010dc513aa1003ba1f873e75dcbe560bbfdc..db269b93df0345a91204851532f55264558b74c5 100644
--- a/Assets/MainAssets/Scripts/Managers/CrowdBotSim_TrialManager.cs
+++ b/Assets/MainAssets/Scripts/Managers/CrowdBotSim_TrialManager.cs
@@ -317,9 +317,10 @@ public class CrowdBotSim_TrialManager : MonoBehaviour, TrialManager {
 
         if( crowdpub != null)
         {
-            int start_index = 1; //player
+            int start_index = 0; 
+            if(player_in_sim) start_index++; //player
             if(robots != null) start_index += robots.Count;
-            crowdpub.UpdateAgents(currPos.GetRange(start_index, currPos.Count-start_index), agentsList);
+            if(currPos.Count - start_index > 0) crowdpub.UpdateAgents(currPos.GetRange(start_index, currPos.Count-start_index), agentsList);
         }
 
         sims.doStep(ToolsTime.DeltaTime, currPos, player, agentsList, robots);