diff --git a/AlgebraicDataflowArchitectureModel/models/TableUI.model b/AlgebraicDataflowArchitectureModel/models/TableUI.model
index 8019ee0..defb520 100644
--- a/AlgebraicDataflowArchitectureModel/models/TableUI.model
+++ b/AlgebraicDataflowArchitectureModel/models/TableUI.model
@@ -91,7 +91,7 @@
 
 channel EventHandler3(curScId: Str, wid: Str) {
 	in screenTemplates.{curScId="000"}.widgets.{wid="002"}.data(curData: Map, handleEvent3(nextData, wid)) = nextData
-	out screen.widgets.{wid}.data(curData: Map, handleEvent3(nextData, wid)) = nextData
+	out screen.widgets.{wid="002"}.data(curData: Map, handleEvent3(nextData, wid)) = nextData
 }
 
 channel addAccount {
diff --git a/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/SwingPresenter.java b/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/SwingPresenter.java
index ba29908..bdd76dd 100644
--- a/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/SwingPresenter.java
+++ b/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/SwingPresenter.java
@@ -335,11 +335,21 @@
 										if(primaryKeyVisible) {
 											tableDatas[dataCount][0] = dataKey;
 											for(int j = 1; j < columns.length; j++) {
-												tableDatas[dataCount][j] = (String)((Constant) rowData.get(columns[j])).getValue();
+												Constant cellValue = (Constant) rowData.get(columns[j]);
+												if(cellValue == null) {
+													tableDatas[dataCount][j] = "error";
+												} else {
+													tableDatas[dataCount][j] = (String)((Constant) rowData.get(columns[j])).getValue();
+												}
 											}
 										} else {
 											for(int j = 0; j < columns.length; j++) {
-												tableDatas[dataCount][j] = (String)((Constant) rowData.get(columns[j])).getValue();
+												Constant cellValue = (Constant) rowData.get(columns[j]);
+												if(cellValue == null) {
+													tableDatas[dataCount][j] = "error";
+												} else {
+													tableDatas[dataCount][j] = (String)((Constant) rowData.get(columns[j])).getValue();
+												}
 											}
 										}
 										dataCount++;
diff --git a/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/TableDataReceiver.java b/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/TableDataReceiver.java
index fc5883b..f2ad1c0 100644
--- a/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/TableDataReceiver.java
+++ b/AlgebraicDataflowArchitectureModel/src/simulator/interfaces/swing/TableDataReceiver.java
@@ -27,6 +27,7 @@
 	@Override
 	public void onReceiveFromModel(Event event, SystemState nextSystemState) {
 		Expression message = event.getMessage();
+		System.out.println(message);
 		if(message instanceof Term) {
 			MapTerm data = (MapTerm)((Term) message).getChild(0);
 			int colNum = columns.length + (primaryKeyVisible ? 1 : 0);