diff --git a/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java b/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java
index a3d2687..08739af 100644
--- a/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java
+++ b/AlgebraicDataflowArchitectureModel/src/application/editor/Editor.java
@@ -375,7 +375,7 @@
 
 			Map<DataTransferChannel, Object> channelsIn = new HashMap<>();
 			Map<DataTransferChannel, Object> channelsOut = new HashMap<>();
-			Map<ResourcePath, Object> resources = new HashMap<>();
+			Map<Integer, Object> resources = new HashMap<>();
 
 			// create channel vertices
 			for (ChannelNode c: dataFlowGraph.getRootChannelNodes()) {
@@ -455,7 +455,7 @@
 				Object resource = graph.insertVertex(parent, null,
 						res.getResourceName(), 20, 20, w, h,
 						"shape=ellipse;perimeter=ellipsePerimeter"); // insert a resource as a vertex
-				resources.put(res, resource);
+				resources.put(System.identityHashCode(res), resource);
 				getChildResource(resource, resNode, resources, w, h);
 			}
 			
@@ -466,7 +466,7 @@
 					// output edge
 					DataTransferChannel channel = ((ChannelNode) dfEdge.getSource()).getChannel();
 					ResourcePath dstRes = ((ResourceNode) dfEdge.getDestination()).getOutSideResource();
-					graph.insertEdge(parent, null, new SrcDstAttribute(channel, dstRes), channelsOut.get(channel), resources.get(dstRes), "movable=false");
+					graph.insertEdge(parent, null, new SrcDstAttribute(channel, dstRes), channelsOut.get(channel), resources.get(System.identityHashCode(dstRes)), "movable=false");
 				} else {
 					// input edge
 					ResourcePath srcRes = ((ResourceNode) dfEdge.getSource()).getOutSideResource();
@@ -474,10 +474,11 @@
 					Set<Map.Entry<ResourceNode,ResourceNode>> toRes = getResourceDependencyForChannel(channel, model, dataFlowGraph);
 					for(Map.Entry<ResourceNode, ResourceNode> RtoR :  toRes) {
 						graph.insertEdge(parent, null, null,
-								resources.get(RtoR.getValue().getOutSideResource()), resources.get(RtoR.getKey().getOutSideResource()), "dashed=true;movable=false");
+								resources.get(System.identityHashCode(RtoR.getValue().getOutSideResource())), 
+								resources.get(System.identityHashCode(RtoR.getKey().getOutSideResource())), "dashed=true;movable=false");
 					}
 					
-					graph.insertEdge(parent, null, new SrcDstAttribute(srcRes, channel), resources.get(srcRes), channelsIn.get(channel), "movable=false");
+					graph.insertEdge(parent, null, new SrcDstAttribute(srcRes, channel), resources.get(System.identityHashCode(srcRes)), channelsIn.get(channel), "movable=false");
 				}
 			}
 			
@@ -485,19 +486,19 @@
 				// reference edges
 				DataTransferChannel channel = (DataTransferChannel) ch;
 				for (ResourcePath refRes: channel.getReferenceResources()) {
-					graph.insertEdge(parent, null, null, resources.get(refRes), channelsIn.get(channel), "dashed=true;movable=false");
+					graph.insertEdge(parent, null, null, resources.get(System.identityHashCode(refRes)), channelsIn.get(channel), "dashed=true;movable=false");
 				}
 			}
 		} finally {
 			graph.getModel().endUpdate();
 		}
-//		setTreeLayout();
+		setDAGLayout();
 		
 		bReflectingArchitectureModel = false;
 		return graph;
 	}
 
-	public void getChildResource(Object resource, ResourceNode resNode, Map<ResourcePath, Object> resources, int w, int h) {
+	public void getChildResource(Object resource, ResourceNode resNode, Map<Integer, Object> resources, int w, int h) {
 		
 		for (ResourceNode c: resNode.getChildren()) {
 //			w = w - 100;
@@ -509,7 +510,7 @@
 			Object chResource = graph.insertVertex(resource, null,
 					chRes.getName(), 0, 0, w, h,
 					"shape=ellipse;perimeter=ellipsePerimeter"); // insert a resource as a vertex
-			resources.put(chRes, chResource);
+			resources.put(System.identityHashCode(chRes), chResource);
 			getChildResource(chResource, c, resources, w, h);
 		}
 	}
@@ -796,9 +797,11 @@
 			Map<ChannelMember, Map.Entry<ResourcePath, Set<ChannelMember>>> dependency = ch.fillOutsideResourcePaths(ch.getOutputChannelMembers().iterator().next(), JavaCodeGenerator.pullAccessor);
 			for (ChannelMember srcMem: dependency.keySet()) {
 				ResourceNode srcNode = dataFlowGraph.getResourceNode(srcMem.getResource());
-				for (ChannelMember dstMem: dependency.get(srcMem).getValue()) {
-					ResourceNode dstNode = dataFlowGraph.getResourceNode(dstMem.getResource());
-					resourceDpendency.add(new AbstractMap.SimpleEntry<>(srcNode, dstNode));
+				if (srcNode != null) {
+					for (ChannelMember dstMem: dependency.get(srcMem).getValue()) {
+						ResourceNode dstNode = dataFlowGraph.getResourceNode(dstMem.getResource());
+						resourceDpendency.add(new AbstractMap.SimpleEntry<>(srcNode, dstNode));
+					}
 				}
 			}
 		} catch (ParameterizedIdentifierIsFutureWork | ResolvingMultipleDefinitionIsFutureWork | InvalidMessage