Index: lams_tool_scribe/src/java/org/lamsfoundation/lams/tool/scribe/web/actions/LearningWebsocketServer.java
===================================================================
diff -u -r5773f84ed608838de3521ecde87c52f3c72d478c -r7e4b8f931ea9c503f32cbd7d06563fd875219544
--- lams_tool_scribe/src/java/org/lamsfoundation/lams/tool/scribe/web/actions/LearningWebsocketServer.java	(.../LearningWebsocketServer.java)	(revision 5773f84ed608838de3521ecde87c52f3c72d478c)
+++ lams_tool_scribe/src/java/org/lamsfoundation/lams/tool/scribe/web/actions/LearningWebsocketServer.java	(.../LearningWebsocketServer.java)	(revision 7e4b8f931ea9c503f32cbd7d06563fd875219544)
@@ -294,14 +294,21 @@
      * The scribe or a Monitor has force completed the activity. Browsers will refresh and display report summary.
      */
     static void sendCloseRequest(Long toolSessionId) throws JSONException, IOException {
+	Set<Session> sessionWebsockets = LearningWebsocketServer.websockets.get(toolSessionId);
+	if (sessionWebsockets == null) {
+	    return;
+	}
+	// make a copy of the websocket collection so it does not get blocked while sending messages
+	sessionWebsockets = new HashSet<Session>(sessionWebsockets);
+
 	JSONObject responseJSON = new JSONObject();
 	responseJSON.put("close", true);
 	String response = responseJSON.toString();
 
-	// make a copy of the websocket collection so it does not get blocked while sending messages
-	Set<Session> sessionWebsockets = new HashSet<Session>(LearningWebsocketServer.websockets.get(toolSessionId));
 	for (Session websocket : sessionWebsockets) {
-	    websocket.getBasicRemote().sendText(response);
+	    if (websocket.isOpen()) {
+		websocket.getBasicRemote().sendText(response);
+	    }
 	}
     }