diff --git a/src/clickTrainDetector/classification/CTClassifierParams.java b/src/clickTrainDetector/classification/CTClassifierParams.java
index 9768c61f..91d4e8a7 100644
--- a/src/clickTrainDetector/classification/CTClassifierParams.java
+++ b/src/clickTrainDetector/classification/CTClassifierParams.java
@@ -36,7 +36,7 @@ public class CTClassifierParams implements Cloneable, Serializable, ManagedParam
 	/**
 	 * A unique ID for the classifier that never changes. This is important for accessing data selectors. 
 	 */
-	public String uniqueID =  UUID.randomUUID().toString();
+	private String uniqueID =  UUID.randomUUID().toString();
 	
 	
 	/**
@@ -72,4 +72,21 @@ public class CTClassifierParams implements Cloneable, Serializable, ManagedParam
 		return ps;
 	}
 
+	/**
+	 * @return the uniqueID
+	 */
+	public String getUniqueID() {
+		if (uniqueID == null) {
+			uniqueID =  UUID.randomUUID().toString();
+		}
+		return uniqueID;
+	}
+
+	/**
+	 * @param uniqueID the uniqueID to set
+	 */
+	public void setUniqueID(String uniqueID) {
+		this.uniqueID = uniqueID;
+	}
+
 }
diff --git a/src/clickTrainDetector/classification/simplechi2classifier/Chi2ThresholdClassifier.java b/src/clickTrainDetector/classification/simplechi2classifier/Chi2ThresholdClassifier.java
index 8cca8403..e7b78e7d 100644
--- a/src/clickTrainDetector/classification/simplechi2classifier/Chi2ThresholdClassifier.java
+++ b/src/clickTrainDetector/classification/simplechi2classifier/Chi2ThresholdClassifier.java
@@ -119,14 +119,13 @@ public class Chi2ThresholdClassifier implements CTClassifier {
 	public void createDataSelector(PamDataBlock<?> source) {
 		//System.out.println("Create data selector " +" " + clssfrParams.classifierName + "  " + clssfrParams.speciesFlag + " " + clssfrParams.uniqueID ); 
 		
-		if (clssfrParams.uniqueID==null) clssfrParams.newUniqueID();
 
 		if (dataSelector==null || dataSelector.getPamDataBlock()!=source) {
 			//create the data selector
 			//System.out.println("Data selector: " + dataSelector); 
 			if (source!=null) {
 				
-				dataSelector=source.getDataSelectCreator().getDataSelector(clickTrainControl.getUnitName() +  "_" + clssfrParams.uniqueID
+				dataSelector=source.getDataSelectCreator().getDataSelector(clickTrainControl.getUnitName() +  "_" + clssfrParams.getUniqueID()
 						+ "_X2_threshold_classifier", false, null);
 			}
 			else {
diff --git a/src/clickTrainDetector/dataselector/CTDataSelector.java b/src/clickTrainDetector/dataselector/CTDataSelector.java
index 1c6bdade..8fd9e4d7 100644
--- a/src/clickTrainDetector/dataselector/CTDataSelector.java
+++ b/src/clickTrainDetector/dataselector/CTDataSelector.java
@@ -131,6 +131,10 @@ public class CTDataSelector extends DataSelector {
 			CTDataUnit clickTrain = (CTDataUnit) ctDataUnit; 
 
 			if (clickTrain.ctClassifications==null) return false; 
+			
+			if (ctSelectParams.classifier == null) {
+				return false;
+			}
 
 			int nClass = clickTrain.ctClassifications.size();
 			if (ctSelectParams.allowMultipleChoices == false) {
diff --git a/src/clickTrainDetector/layout/classification/simplechi2classifier/SimpleCTClassifierPane.java b/src/clickTrainDetector/layout/classification/simplechi2classifier/SimpleCTClassifierPane.java
index 8ee87ba5..fa2d9a84 100644
--- a/src/clickTrainDetector/layout/classification/simplechi2classifier/SimpleCTClassifierPane.java
+++ b/src/clickTrainDetector/layout/classification/simplechi2classifier/SimpleCTClassifierPane.java
@@ -229,7 +229,7 @@ public class SimpleCTClassifierPane extends SettingsPane<Chi2ThresholdParams>  {
 			simpleChi2Classifier.getDataSelector().getDialogPaneFX().getParams(true); 
 		}
 		if (this.currParams != null) {
-			currParams.uniqueID = this.currParams.uniqueID; 
+			currParams.setUniqueID(this.currParams.getUniqueID()); 
 		}
 		
 		return this.currParams=currParams;