diff --git a/AlgebraicDataflowArchitectureModel/src/simulator/Event.java b/AlgebraicDataflowArchitectureModel/src/simulator/Event.java
index ac88b99..c841b23 100644
--- a/AlgebraicDataflowArchitectureModel/src/simulator/Event.java
+++ b/AlgebraicDataflowArchitectureModel/src/simulator/Event.java
@@ -352,6 +352,8 @@
 					} else if (channel.getReferenceChannelMembers().contains(dependingMem)) {
 						// Calculate message constraint from a reference state transition
 						messageConstraint = channel.calcMessageConstraintForReferenceMember(dependingMem, null, resouceStateAccessor, null, substitutedPositionsInMessageFromChannels);
+					} else {
+						continue;
 					}
 					if (unifiedMessage == null) {
 						unifiedMessage = (Term) messageConstraint;