Improve error message meaning

Change-Id: I085d0f25115e6acd0804b8d547aa58501191b429
diff --git a/plugins/contracts/org.polarsys.chess.contracts.profile/src/org/polarsys/chess/contracts/profile/chesscontract/util/EntityUtil.java b/plugins/contracts/org.polarsys.chess.contracts.profile/src/org/polarsys/chess/contracts/profile/chesscontract/util/EntityUtil.java
index a061c6f..4e427c7 100644
--- a/plugins/contracts/org.polarsys.chess.contracts.profile/src/org/polarsys/chess/contracts/profile/chesscontract/util/EntityUtil.java
+++ b/plugins/contracts/org.polarsys.chess.contracts.profile/src/org/polarsys/chess/contracts/profile/chesscontract/util/EntityUtil.java
@@ -1820,7 +1820,7 @@
 		if (initialState != null) {

 			return initialState.getOutgoings();

 		} else {

-			throw new Exception(stateMachine.getName() + " does not have the initial state.");

+			throw new Exception("The state machine of "+((Class) (stateMachine.getOwner())).getName() + " does not have the initial state.");

 		}

 

 	}