handle NULL reference exception

PROMS/DataLoader/Transitions.cs

@@ -355,7 +355,8 @@ namespace DataLoader
 							break;
 						}
 					}
-
+					if (prc != null)
+					{
 						// For each transition that points to the A0, make it point to the proc.
 						// First, find all of them by getting transitions with the A0 (dummy
 						// transition record).  Then update the to or range id in the transition
@@ -368,6 +369,7 @@ namespace DataLoader
 						foreach (TransitionInfo tir in til) UpdateTranDataForA0(prc, tir.TransitionID, true);
 					}
 				}
+			}
 			foreach (string str in RemoveFromDicTrans)
 			{
 				dicTrans_ItemIds.Remove(str);