X-Git-Url: http://source.jalview.org/gitweb/?a=blobdiff_plain;f=src%2Fjalview%2Fgui%2FTreePanel.java;h=2727db14171e6e947b19801acb9db2e2061e7aa6;hb=8ac25f08dacd4759548f62332004288b0e86fdee;hp=82f356588c0f982f5e92bb0d9fde96ddeffe6a48;hpb=90c2f45e60ed604705e81dd8af31bf0bfd3dbdef;p=jalview.git

diff --git a/src/jalview/gui/TreePanel.java b/src/jalview/gui/TreePanel.java
index 82f3565..2727db1 100755
--- a/src/jalview/gui/TreePanel.java
+++ b/src/jalview/gui/TreePanel.java
@@ -155,7 +155,10 @@ public class TreePanel extends GTreePanel
       @Override
       public void internalFrameClosed(InternalFrameEvent evt)
       {
-        av.removePropertyChangeListener(listener);
+        if (av != null)
+        {
+          av.removePropertyChangeListener(listener);
+        }
       }
     });