diff --git a/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/channels/ChannelTablePanel.java b/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/channels/ChannelTablePanel.java
index 8fcb7e1..dda6dab 100644
--- a/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/channels/ChannelTablePanel.java
+++ b/src/main/java/org/micromanager/lightsheetmanager/gui/tabs/channels/ChannelTablePanel.java
@@ -8,6 +8,7 @@
 import org.micromanager.lightsheetmanager.gui.components.Panel;
 import org.micromanager.lightsheetmanager.model.LightSheetManagerModel;
 import org.micromanager.lightsheetmanager.api.data.MultiChannelMode;
+import org.micromanager.lightsheetmanager.model.channels.ChannelSpec;
 
 import javax.swing.JLabel;
 import java.util.ArrayList;
@@ -79,14 +80,18 @@ private void createEventHandlers() {
 //            repaint();
             System.out.println("add channel");
             table_.getData().printChannelData();
-            asb.channels(table_.getData().getChannelArray());
+            final ChannelSpec[] channels = table_.getData().getChannelArray();
+            asb.channels(channels);
+            asb.numChannels(channels.length);
         });
 
         btnRemoveChannel_.registerListener(e -> {
             final int row = table_.getTable().getSelectedRow();
             if (row != -1) {
                 table_.getData().removeChannel(row);
-                asb.channels(table_.getData().getChannelArray());
+                final ChannelSpec[] channels = table_.getData().getChannelArray();
+                asb.channels(channels);
+                asb.numChannels(channels.length);
                 table_.refreshData();
                 System.out.println("remove row index: " + row);
             }
diff --git a/src/main/java/org/micromanager/lightsheetmanager/model/channels/ChannelTableData.java b/src/main/java/org/micromanager/lightsheetmanager/model/channels/ChannelTableData.java
index 85f0d2f..6b72a64 100644
--- a/src/main/java/org/micromanager/lightsheetmanager/model/channels/ChannelTableData.java
+++ b/src/main/java/org/micromanager/lightsheetmanager/model/channels/ChannelTableData.java
@@ -18,6 +18,7 @@ public ChannelTableData() {
 
     public ChannelTableData(final ChannelSpec[] channels, final String channelGroup) {
         channels_ = new ArrayList<>();
+        // TODO: Objects.requireNonNull
         if (channels != null) {
             Collections.addAll(channels_, channels);
         }